No, for your short RV rental vacation trip, you do not need to worry about such intricate RV topics. It is the responsibility of the RV rental company or the RV Owner to supply you with the water pressure gauge if they feel the need.
Nevertheless for your information an RV Water Pressure gauge is a small device that helps regulate the water pressure between the RV Park water outlet and the RV’s water plumbing. This is particularly useful when RV parks have unreliable water pressure and high pressure can damage the RVs plumbing system. Please refer to the following youtube video for more information: