A1: You get them from the different temples

A2: The first five you get through the storyline. You can get Yojimbo by going to the calm lands then go north to the place where you fight Defender Z. somewhere in that area you will find a path that goes under the bridge follow it and you will come out in an area near a cliff. go to the left and there is a cave go in it and follow it to the end where you will find a summoner who summons yojimbo after you beat him there is a warp pad where you can warp into a room where you will find yojimbo you will then have to pay him around 230,000 gil and he will ask you what you wish of him select to defeat the strongest of enemies and he will join as an aeon.to get Anima you have to have all of the aeons except for the magus sisters. you also have to get the destruction spheres and open the treasure chests revealed by the destructions spheres which destroys something and reveals the chests.the last chest youll find by going back to zanarkand and doing the puzzle youll then get a destruction sphere which you use to put in the sphere hole in the wall by the computer screen the screen will disentigrate and reveal a chest. then go to the Baaj temple (x coordinate 11-16 y coordinate 57-63on the search map in the airship) and dive of of the cliff ledge and swim towards the opening between the two statues and you will fight geosgaeno he has about 32,000hp and you will need armor with stoneproof which you can custamize by using 20 petrify grenades which you can steal or get from the lizards in the omega ruins. then go into the hole and keep swimming until you find a room with a bunch of statues go up to each statue and press x a rune behind it will glow and once you go up to all 6 you can go into the door at the back of the room a woman will talk to you and you will get anima.how to get the magus sisters is explained in another question on this page. I hope this was of help

A3: The coordinates to the omega ruins are
x coordinate y coordinate
69-75 33-38

A4: You get most o them in the story but you can get a few other