I had the same problem a few years ago and eventually just gave up. Probably my loss but after hearing rightly or wrongly about the "pickeball wars" and "pickleball snobs" (not unlike golf) on the courts especially with regard to newbies maybe in the end I was better off. It did often seem that "friends of the right people" had no problem getting started with classes.
Suggestion for ALL. NEVER use your primary email address
as a username. You are inviting spam and more because there are "bots" all over the web harvesting email addresses. Best off using a throw-away email address if necessary or just a username as most do.
Email-address harvesting - Wikipedia
"