Welcome to the Biewer world and congratulations on your litter. No, you don't have to join a club at all if you don't want to. As you have probably seen, the Biewer world is surrounded in politics and not always a fun place to be, so I can truly understand why people would hesitate to jump out there. The good thing about belonging to a club though is it opens you up to a lot of information and allows you to help work on the future of these dogs outside of just your own breeding program.
There are currently three active Biewer clubs (BAPPC, BBCA, BTCA) in the U.S. If you decide to join one of the clubs, the best advice that I can give is to research each club and find out what they stand for and the paths that they are following and then join the one that closely mirrors what you believe and the goals that you have. Unfortunately, I see many people joining clubs out of friendship. While I agree that wonderful friendships can be formed within a club, people should be joining clubs with the dog in mind. After all, that is why the clubs were formed and that should be everyone's priority.
Good luck with your Biewers and your decisions!