Great question! Relays aren't involved in curation or discovery, so it fall on the client.
You can request very broad subscriptions from relays! For example, here is a site that subscribes to everything, showing you a gods-eye view of events streaming into a relay:
You can request very broad subscriptions from relays! For example, here is a site that subscribes to everything, showing you a gods-eye view of events streaming into a relay:
https://nostr.info/relays
Events have different "kinds", so you can filter this based on the type of traffic you are looking for (like public posts or user profiles).
Platforms like damus.io are more user-friendly, and offer better tools for discovering users and content.
You can subscribe to a user's feed via their pubkey, so discovery methods typically revolve around learning pub keys.