I can chime in here. I self-host a lot of my apps using Cloudron.
Super simple to install on a spare computer, it makes it easy to deploy free and open-source software. Here is a video I made on it:
For apps that are not on Cloudron and need a Linux server, you can use Proxmox. Essentially, it lets you run multiple servers in one computer.
Proxmox is more technical, so start with Cloudron.
BACKUPS
Cloudron has several backup options, but I use the S3 option. I installed MinIO (open source S3 file storage software) on a second computer, which Cloudron then connects to weekly and pushes a backup of itself to. I made a video about MinIO here:
This should get you started. If you have any questions, feel free to ask.