Do you have any indication of air in the system when turning on the taps?
If so you need to check the inlet debris filter on the pump; clear plastic 2" round , screws off the pump by hand, and look for cracks. If cracked , replacement is in order. $10 or so.
If your not getting air out of the taps then you have to check the plumbing attached to the pump, if the pressure side is ridged plastic, you will need to install about a foot of drinking water suitable flex hose to isolate the pump, from the rest of the plumbing, and check all the runs of water lines for loose mounts.
Fittings and hose at any RV store.