You can "subscribe" to hashtags which allows you to follow them in a column ("timeline") as you would your followers, mixing hashtags into a single timeline if you wish.

There's also the option of adding "featured hashtags" to one's profile, allowing a user to search for users of a particular interest.

Along with the "Federated Timeline", which others have mentioned, and your follower's boosting posts (akin to retweeting) I've found it quite easy to find a diverse list of people to follow and interact with.