So I got city water about 8 months ago, I have no need for the pump house or anything in it, noticed the backyard was flooded, and the blue pressure tank just has water pouring out the bottom and around the sides where the blue meets the black part, how do I remove this tank and plug the hole? I just dont know if I need to cut the PVC pipe going to the tank or if theres a way to twist it and it disconnects from the black base or what any help please?

I would cut the PVC pipe going to the tank and glue a cap on it.

or slide on a sharkbite cap.

Turn off the power to the pump. The tank should unscrew. From there you can either replace the tank or simply install a plug into the old threads. Personally, I would keep the well and have it supply the outside hose faucets; it is a really cheap way to water the garden and wash cars if you desire.

"I would keep the well and have it supply the outside hose faucets"
if we do that in MA we have to have a testable backflow preventer on the city water service entering the house.
no telling when or if a homeowner would decide to use the well water to fill a toilet and save some money. all sorts of cross connections possible.

If a pro did repiped it, they know better; if a homeowner did it, they won't get it inspected and thus won't install a back flow regardless. Seems a little anal on the part of the city considering. Just saying.

it is not the city, it is a state of MA plumbing code.
they want to be 100% sure that no well water can get back into the public water supply.
anyway, a homeownwr can not perform plumbing in their own home unless they hold a valid MA plumbing license.