to know what IDA is, you can google « what is IDA Pro » and you will have your answer ^^
And, tbh before learning how to hack a game, i would learn a programming language cuz i did this error, i tried to learn everything about hacking without actually knowing how the program works, and it was basically a brain break
No need to be a pro at coding, but coding some small projet will help you to understand the logic even if it is the basics, after that you will easily evolve !
I’m learning Obj-C
Regarding your first game, i would suggest you, one you have basic programming, hacking a unity game, and you will know why after few tutorials ! make some simple offsets patching will be nice for a first hack.
for game hacking, you can also look at Android/PC tuts, it’s basically the same things, i mean the similar way to find offsets...
Good luck, and google will help you a lot if you have questions !