Tick anything you already have, in any order. Quests unlock once this is done.
TryHackMe and HackTheBox give you deliberately vulnerable machines you are allowed to attack. This is where the whole field learns, and it is mostly free.
Open TryHackMe2 things left above. Quests are real things you go and do, so they only make sense once you have what you need.
First one waiting: Set up a legal home hacking lab