nowadays sites usually dont provide rss, so you need something to convert webpage to rss, like rssbrige or rsshub, even rssproxy sometimes. rsshub & rssbrige also have categories/catalogs you can check if anything interests you. i wouldnt suggest follow forums with rss, because they tend to update very frequently essentially overwhelm your feeds, but i followed several cat related just for fun.
https://docs.rsshub.app/guide https://rss-bridge.org/bridge01/
linkwarden can grab webpage for offline access. but i prefer archivebox, archivebox let you choose which method will be use, linkwarden will use every method in configuration. it’s generally fine but i want some flexibility. archivebox also have more method to cache webpages. the downside of archivebox is its kinda unpolished, also they dont have a webui for mobile device.
and some webpages are too complicated for those apps, like require login or something, singlefile is a good solution, it directly download the webpage with your browser.
https://github.com/gildas-lormeau/SingleFile