@lyncia depending how deep you are into it, i think it helps to notice that basically everything has tab completion--and even when it doesn't look like it, esc then tab will still probably do completion for what you're looking at

this is basically the biggest way i use things i'm unfamiliar with in emacs

also, if you haven't used it much, C-h is game-changing! it turns emacs from a black box into something where you know how to get help for anything you're unfamiliar with

like, C-h m will describe the mode you're in right now and list all the keys that are available, C-h k tells you what any key or click does, and if you did something weird, C-h l lists all the things you just did with the commands they ran right next to them. C-h i even brings up actual full ebooks about pretty much everything you can just...browse (C-h ? lists all the things C-h can show help for)