You have the right idea. You need to supply locations for the “Start” and “end” of the trace. You have them both as 0. For start you should probably have the location of the player in the world. Then you need to create a point in space in front of the character to set the end of the trace. You should use “Get Rotation Xvector” get get a vector of the forward rotation, multiply it by some scalar to set the trace length, and then add that to the player world location.
I am not sure what you mean about converting from 2D to 3D though.