The bell in the top bar shows the latest ones, and View all opens Command Center, then Notifications. You are notified about replies, quotes, reposts, rockets, mentions and follows, about battle challenges, about rewards ready to claim and about events on coins you created.
Open Command Center, then Settings, then Notification settings. Each of the four categories has a Bell switch and an Email switch. Email works only after you add an address and open the link we send. Saving asks for a free wallet signature.