After the opening sequence in Zanarkand, Tidus will find himself in the Zanarkand Submerged Ruins. Use the mini-map in the top-left corner of the screen to assist you with navigating around the area. The red arrow indicates where you have to go.
Swim northwest until you find a flight of stairs sticking up out of the water. Climb them to find an Al Bhed Compilation Sphere laying on the ground.
Throughout your travels, you will find items called 
Al Bhed Primers which will assist you with deciphering the language of the Al Bhed people whom you will meet later on in the game.
If you have ever played through Final Fantasy X previously you can use your old save data to automatically load in Al Bhed Primer data from your previous game. This will allow you to decipher the Al Bhed language right from the start of the game.
There is also a treasure chest to the south of the Al Bhed Compilation Sphere that contains two 
Potions. Jump back into the water after you have collected them.
On the right side of the screen (east side of the map) is a treasure chest that contains 200 gil (near some Al Bhed graffiti). Make sure to grab it before you head north in to the next area.
Use the Save Sphere to your left and, as one more quick reminder, get into the habit of always saving! You will save yourself a lot of potential grief later on down the line and the process of touching the Save Sphere will refill your HP and MP.
Take the path that goes out and off to the left to find a treasure chest containing a Hi-Potion.
Then head to the north and continue along the pathway and Tidus will be thrown into the water. Swim north towards the Save Sphere to initiate the next boss battle.
In Game Description: Covered with thick scales. Vulnerable to magic.
HP: 32,767
This battle starts off as a battle against three Sahagin (fish like creatures). Two quick attacks from Tidus will make easy work of them. The third will be killed by the actual boss.
This is another boss battle where you cannot be killed. Geosgaeno’s attacks will always hit you for 50% of your HP. The battle will end prematurely though after a few attacks so don’t waste any of your Potions trying to keep yourself alive.
Tidus will make a frantic escape from Geosgaeno at the end of the battle. The chase will lead him inside the actual Zanarkand Ruins. Head north through the corridor and into the next room.
There is a Save Sphere in the southwest corner of the room indicated on the mini-map by a white square. Go through the doorway beside the Save Sphere and into the next room. Examine the box on the ground to obtain a 
Flint.
Go back to the main room that Tidus started off in and head east. To the right of the large locked door is a chest that contains an X-Potion.
Now go north through the doorway. There is a treasure chest right at the entrance (near where the camera is located) that contains an 
Ether.
Follow the stairs upwards and grab the Withered Bouquet at the top of the staircase.
Continue following the hallway along back into the second floor of the main room to find a treasure chest containing a Hi-Potion.
Go back to the center of the main room and examine the fire pit to light the fire. Tidus will fall asleep in front of the fire that he sets and will wake up just before the fire goes out. As he looks around the room, he notices a strange creature watching him…
HP: 1,500
This is another fairly standard boss fight. The only difference is that this time you should be prepared to use a few Potions in order to stay alive. Klikk is actually capable of inflicting some damage.
You will be interrupted part way through this fight by some Al Bhed characters. One of them will join the battle and assist Tidus. You’ll get a quick overview of how 
Grenades work. Follow the instructions and use a Grenade on Klikk and continue to attack with Tidus until the battle is over.
The character that joins Tidus starts off with only two Grenades in her possession but you can use her 
Steal command under on Klikk and nab one more from it.
Steal:
Grenade
Drops:
Ability Sphere
The strangely dressed people who burst in to the Zanarkand Ruins will take Tidus with them as they leave the area. This group of people are known as the “Al Bhed”. The next scene takes place on their ship.
Before you do anything, speak to the girl in the red outfit to get a quick overview of the Sphere Grid system. This is the leveling up system used in Final Fantasy X and it is used to teach characters new abilities and improve their stats.
Check out the Sphere Grid section for more information on this system.
Go in and use the Sphere Grid after you’ve gone through the tutorial. Use it to move Tidus one space and then use the Ability Sphere that Klikk dropped to activate the Cheer ability. This is all that you can do in the Sphere Grid for now.
Talk to the Al Bhed on the left to receive three Potions. There is an Al Bhed Primer (Vol. I) on the ground at the back of the ship. Make sure to grab it and then make sure to save your game.
Throughout the game you will come across Al Bhed Primers which can be used to teach you what the Al Bhed are saying, letter by letter. Letters that you haven’t learned yet will show up as normal white lettering whereas letters that you have learned will be captioned in pink when characters speak Al Bhed.
This guide will point out the locations of all 24 of the Al Bhed Primers as you come across them. Check out the Al Bhed Primer side quest section for more details.
Speaking in Tongues
Obtaining your first Al Bhed Primer will reward you with the Speaking in Tongues Trophy. You can also obtain the Master Linguist Trophy if you manage to find all 26 of them, so make sure you don’t miss any!
Speak to the girl in red one more time to get an overview of your next mission.
The next part of the game takes place underwater. Swim down and follow the chain downward in the direction of the red arrow. Use the 
Button to dive downward. You and the girl in red are headed down to salvage some wreckage and explore some ancient ruins.
This is the first time in the game where you will be thrown into random enemy encounters as you are exploring so don’t waste too much time getting to each destination. Thankfully the enemies that you encounter in this first area are very easy to defeat.
Use the Save Sphere to refill your team’s HP and MP in anticipation of some fights that will be coming up.
Examine the control grid to watch Tidus start hammering away on it. The girl in the red will now lead you in the proper direction.
Follow her into the next room and then press 
Button near her to get the generator started. As the two of you exit, you will be thrown into the next boss battle.
In Game Description: Retreats behind the column after taking damage, where it cannot be attacked. Hits all targets with Nautilus Charge on the next turn, inflicting great damage. Use trigger commands to stop it from unleashing Nautilus Charge.
HP: 2,200
Have Tidus use the Attack command for each of his turns and have the girl in red (indicated as “????” in the battle screen) use Grenades for each of her turns. You can steal more Grenades from Tros using her Steal command if you run out.
Tros will go out of range from time to time. The game will provide you with a brief overview of Trigger Commands once it does. Press 
(Left) Button on the control pad to view Trigger commands the exact same way you did to use an Overdrive attack.
You now have the option to use the ‘Stand By’ command. ‘Stand By’ will have the character hold off from attacking and will also cause the character to regain some HP. And because you cannot hit Tros while it’s on the opposite side of the room, this is a perfect time to use the ‘Stand By’ command with both characters.
The second time the boss goes to the opposite side of the screen you will be presented with the a Trigger Command called ‘Pincer Attack’. Choose this option to have Tidus and the girl in red (????) attack Tros from both sides.
The boss will no longer be able to escape to the other side of the screen. A few more hits should take it down.
Steal:
Grenade
Drops:
Power Sphere
Swim over to the girl in red (????) indicated by a red arrow on the mini-map to initiate another cutscene. Follow the girl in red (????) after the cutscene finishes.
The Al Bhed will still treat Tidus with disdain once they return to the Salvage Ship. The girl in red will introduce herself as Rikku. She is one of the characters who will be permanently joining your party later on in the game!
After Tidus and Rikku finish their conversation, the Salvage Ship will be attacked by Sin. Tidus will be thrown in to the water during this attack and will be sucked in by Sin again.
This time Tidus will wake up on the shores of Besaid Island.
