Sprite Sheet and how do i make that work?

Alright so i previously just asked on how to make a workable GIF which works great, but this method will cause a ton of problems and uploading a ton of images frame per frame. Someone mentioned using a SpriteSheet and changing the image position. only problem with that is i dont know the first thing about changing the tile position of an image as far as roblox studio goes.

Heres a little as to why this is a huge issue. I am making a Pokemon game, (Yes i know there are a lot and such but to me this would be a great start on studying scripting) and i plan on uploading all of them eventually. Anyways each GIF file has over 30+ frames and i dont want to load all those frame into roblox, plus i heard all those frames cause lag, and its also unnecessary coding in my opinion. So thats why im turning to SpriteSheets.

I have looked everywhere for a tutorial on this and find everything but that, ive tried using the Toolbox but that was a fail. So this is why im coming here. I understand this is not a requesting site so i wont ask for anyone to make a code, but if anyone knows how i could start on that or to even know of a tutorial or something that would help that would be greatly appreciated.

I am only a basic scripter i dont know much about advanced scripting yet. I try to figure out my problems and do as much research as i can before i come here but for this i truly cant find an answer to. I already made a Spritesheet and have uploaded it to roblox, but i dont know how to work on it..