I was trying to find out if there is a law that states after a mobile home is past a certain year in age, it cannot be moved to another trailer park. I live in Mesa AZ. Thank you

Mobile homes are usually excluded under most state housing laws. Mobile home parks can set their own laws regarding age of homes. Remember,they are typically depreciating assets.
Search "AZ mobile home laws.". Check with a mobile homemover, some will not accept liability for the house if it is too old, in their opinion, to be moved.