Network – Java Network UDP Pong

I've been learning Java alone for a few months now and I just created my first game, Pong, with menus / buttons, artificial intelligence issues, one / two players, and so on. Everything works fine, but I want to explore more the multiplayer mode. Games. I realize that Pong is not the best game to do this because it's so fast, but where do I start? I've read a bit about UDP, servers, clients, sockets, etc., but I have a hard time understanding. I've also created a simple TCP chat server, but not with UDP. Some of you not wishing to write a long answer, is there a good example of Pong UDP Network that someone is willing to share?