Yacht is a great UI for starting a container, especially for self hosting, there are a good amount of tutorial online.

I personally also host

• syncthings that will sync my app settings on the phone, and push it to my cloud drive,
• pi-hole to block trackers. I generally let ad through, but not trackers.
• jellyfin for media library
• transmission for (cough, cough) seeding fedora, mint and other free and open source, and 100% legal stuff.
• home assistant for automations.

Some other things you can try:

• a home Minecraft server, not exactly FOSS, but if you are into it, you should do it.
• Nextcloud for syncing photo and documents, but remember to keep a offsite backup.