What is best way to manage health/stamina/unlockables for each level?
(By level i mean when player is level 4 he cant slide but when he is above level 6 he can).
Hello Player_003, thank you for posting your question.
There are a couple of ways to go about this:
The most common is by using a Game Instance. There are quite a few brief tutorials on this subject if you would like to review one.
WARNING: This is an external link and as the end user, you are responsible should something happen to your device when you choose to click a link or follow steps that are not endorsed by Epic.
Mathew Wadstein: HTF do I? Save Variables between Maps ( UE4 )
Additionally, I would look into SaveGame classes for maintaining your values across the game.
I hope this helps.