You use the hashtags that match your interests, eg I wanted more Python content in my timeline so I typed #python into the search box at mastodon.online and fol

You use the hashtags that match your interests, eg I wanted more Python content in my timeline so I typed #python into the search box at mastodon.online and followed the tag. I didn't need to use an external site for this, just the Mastodon site. Now I'm seeing posts from people discussing Python stuff which gives me a pool of people to choose to follow. Now that I've got some people populating my timeline I can unfollow the tag if I decide it gets too noisy.