madawg70, Welcome to Physics Forums!
If you were in a spaceship on your way directly toward Jupiter, say, as you got closer Jupiter's gravity would accelerate you towards it. This answers the first part of your question.
As for the second part, "reaching out and lock on its gravity and magnify it for acceleration", that seems impossible. There is a mechanism interplanetary spacecraft use called "gravitational assist", or "boost". A quick Google search would explain for you how that works.
Feel free to ask any other questions you have right here. Members of PF are always willing to assist a true searcher learn more science.
Cheers,
Bobbywhy