This is the largest aggregation of resources for aspiring DPC doctors. There are guides to DPC-relevant state and federal regulations, information on how to start a practice, compilations of conference recordings, a list of upcoming events, a fascinating blog, and the DPC Mapper. Spend some time clicking around.
DPC Docs is by far the most active online community for direct primary care. You can get your questions answered, find templates for legal/marketing documents, and—if you're still in the system—get free therapy. It's a secret group, so you have to be invited to join. If you know an existing DPC doctor, ask them to add you. Otherwise, message one of the Page Admins: Dr. Degnon, Dr. Dickinson, Dr. Davis, Dr. Phillips, or Dr. Benson
The DPC Alliance formed in 2018 and is an increasingly valuable resource for DPC docs.
The D4PCF puts on the largest annual DPC conference, runs a direct-care-focused radio show, and have an email newsletter that's worth checking out.