I think everyone that selfhost their RSS-feeds have at one point or another thought “now what?”.
I have 3 recommendations that might help get you started:
feedspot is a great place to start to just discover what’s out there.
GitHub releases can be followed as RSS (atom) feeds. This is a great way to keep up with changelogs for services that you selfhost. For example, here is the RSS/Atom feed for Jellyfin: link
Do you listen to podcasts? These can usually be found as RSS-feeds and is a great way to get your daily dose of news on your morning commute.