Ceres meant 'any game other than GOIO'. I mean, even on casual or server dm in CS:GO people don't waste time teaching you. You learn or you die. Some people (like WarOwl) upload some tutorials on youtube, but nobody can "teach" you how to control your recoil or throw smokes. They can show you, they can explain, but basically you have to learn it yourself.
In CS:GO you can:
1) play with bots on whatever map you want
2) make exec of whatever you want basically (my brother have a warmup exec where he creates team dm with harmless bots and you're alone on your team and enemy team is like 8 harmless bots, it's purpose is to warm-up shooting headshots)
3) create an empty server of whatever map you want to practice whatever you want (usually all kinds of grenades).
In GOIO you can basically fly on one empty map (Dunes) and create some dummies. Also GOIO doesn't have anything any skills worth practicing except maybe piloting.