You should check your RVs tire pressure before every travel day. It might seem overkill but its important to ensure safety, prevent blowouts, and extend the lifespan of the tires. DO a quick check on the day you plan to travel with a simple tire pressure gauge, or better yet use a TPMS (Tire Pressure Monitoring System). Safe travels!
What tory said. Plus, make sure to check the pressure when the tires are cold, meaning before you’ve driven more than a mile or so (driving heats up the tires, which in turn increases the air pressure inside them).