So you're just getting started in Mastodon huh?

Here's a neat thing. On the web interface you can search for a Hashtag.

Same as you can on Twitter.

Something like #Ukraine, for example

But on the search results, see that little user icon on the right? Click it and you'll follow it as if it's a user!

New posts with that tag will arrive in your home page, even if you don't follow the author yet