How do i explain the rules to my brother?

Recently a pickleball court has opened near my house, and i play regularly with my brother and friends and im pretty decent, for context he used to play a lot of tennis, he refuses to believe that the ball bouncing off the net is a legal serve (it did not land in the kitchen and landed on the correct side) and doesnt think second serve is a real rule. I showed him the proof on google but he doesn’t believe me. Can you guys pls help?