Hey @Csak_Te!
Everynone has definitely got you most of the way there. What I would typically do here is use a LookAt node which will get you the vector between A and B (use Get Location nodes for getting start and finish) then multiply that by a Float to get your Impulse! Also just make that Float a variable for easy adjustment. It’ll be a lot more controllable than relative position as that can get crazy variable based on the locations you have, and not often shoot in the correct direction.
Hope this helps! 