The one way I know might work is tracing between two sockets, but are there a simpler way? And where can I find info about health systems? Can’t find even the smallest mention of that.
The socket tracing thing should work fine for all kinds of straight weapons. For more complicated things (e.g. a doubleheaded axe) you could create a collision shape for the blade and set the Collision mode so that it overlaps with Pawns. In the blade’s BeginOverlap you can then check whether you hit an enemy.
As far as I can tell, UE4 doesn’t provide a health system out of the box. Tha said, the Actor class has functions and events for handling damage. Adding a health variable and changing it when damage is received should therefore be pretty simple. Check out the Actor documentation to learn about the damage functions.