What other's already said, go to the Wolfs Den map in La Noscea and open your PvP page.
There you can look up all your avaible skills, read what they are doing, as PvE and PvP skills work differently.

There are also target dummies in Wolfs Den so you can practice the skills and get used to them.
Also, PvP "Sprint" is a toggle with no duration timer. Good think to remember.


I agree that as a new player not knowing these things, joining a PvP game and have no skills is bad design.
The game should at least have all PvP skills automatically put on your PvP hotbar.
Then the player can relocate them as they want.