sooo hey guy 
i made this in ue now and it works for me, it shoots every 5 seconds a ball towards the player( with homing effect, but you can easily outgo this by ur initial position and outgoing destination).
you have setted the float x,y,z variables but this dont work that way , if those are the fixed values simply put in those values in the make vector function and return them as B-vector for the Vlerp
THE IMPORTANT THING HERE:
connect the update from the timeline to a “Set world location” note , with the moving actor Root component as target and the lerp vector as new location .
your timeline should look like this :
because u lerp from 0 to 1 (0 % to 100%) over a specified time.