I have a pressure pump that pumps water from a tank but as soon as the water is turned on the pump is going non stop with the pressure gauge going up and down.

So you appear to have a booster pump. What is your water supply, city or well? Water movement of that magnitude would show up somewhere. Crawl space? Basement? Follow all the lines to see if you can see or hear a leak.

that pumps water from a tank

Do you mean you are pumping from a holding tank? If so, do you have a pressure tank you are pumping into?