If you finding that you have lower flow in just one water outlet (like the bathroom or the kitchen sink vs. showerheads), before digging into the plumbing to problem-solve, be sure to check the screen on the faucet head itself. RV park water is notoriously full of grit, even if you have an inline filter (which can also release some charcoal bits), so your screen may simply be full of sediment restricting the flow.
And while you are at it, if you are getting some odors in your sink, don’t forget to clean your trap of hair and gunk. People often blame their gray water tank for odors that are really just a drain trap full of crud. Most just hand-screw off and are easy to clean out regularly.
This tip applies to motorhomes, travel trailers and fifth wheels.