Generally speaking. Adding collision to the sword would fine. However most people would say to add a collision sphere to the Character where you want his “attack range” to be. Then you can do something like event begin overlap, cast to (thing you wanna hit), as (thing you wanna hit) promote to variable “MeleeTarget”.
Then on a separate event. Custom event “Swing sword” get MeleeTarget> is valid Bool+Branch= true apply damage.
Hope this helps.