Look up debug helpers, they can draw the line trace so you can visually see it. Quick way to test is make sure everything is set to blockall, this will let the line trace hit. Make sure collision is enabled on your actors and that the actors have a mesh with collision data, or you are at least adding a simple collision object to the actor. also there is multi line trace vs single line trace, which will allow you to do overlap tests and line trace through multiple actors, but depending on your needs you might not need that one.