Facebook is certainly a wonderful tool. I belong to a private FB page for homeschoolers who have children with my daughter’s genetic disorder. How they learn is a little different than the typical child, so it helps to have others in a similar situation to offer suggestions.
Local co-ops. You can google info and find out where they are. Many churches also offer support groups or links to homeschool groups in the community.
HSLDA also has a links page where you can look by state/region.
Websites likes this one, which offer a forum, are also very helpful. The best sites have veteran homeschoolers and “newbies” communicating. There is no one “right” way to homeschool and everyone comes to it from a different perspective. I’m a better homeschooling parent because of the connection I’ve made with other parents.
Libraries. My local librarian is FANTASTIC. (We’re on a first name basis since I’m always in there). She knows I homeschool, and has made an effort to link me to other parents in our community. She also knows when special events are being held (and not just at the library) so she is a valuable source of info!
Hope this helps. I was just thinking off the top of my head.