These two sites provide excellent information on learning how to use Mastodon. Check them out if you need help figuring out the various Mastodon features and how things work.
Within Mastodon you can follow @email@example.com to see posts with tips on using Mastodon, and @FediFollows@social.growyourown.services for posts of interesting accounts to follow. Both are excellent resources when getting started.
Take a look at the Apps page for different ways to access NorCal.Social.