Creating Class System in Generic Shooter

First off im somewhat new to UE4, so please be gentle =)
Secondly i have purchased generic shooter, to which i plan on trying to create a ww2 shooter,
One thing im unsure about is how to properly get a Character class system working with it.
I have created a simple widget which i an call on at the team selection screen,
but im unsure on how to properly have it use this interface and possess a pawn when entering a map,
Im sure some others here have generic shooter and may be able to steer me in the right direction.
Any tutorials or help is greatly appreciated =)