Create a master Ability blueprint - an Actor Component. Encapsulate logic and variables all abilities share.
- enabled, stats, range, damage, duration and whatnot
- functions/events/methods for Use, Cooldown, Upgrade and so on
- visuals for the abilities
- anything else you need
Create a child for each ability providing they need unique functionality. Give the player character all abilities but keep them disabled. Enable as needed.
The following video is a foot in the door of the components how-to: