I learned about this book written by Adam who founded the SeaGL conference.

https://selfhostbook.com/

I’ve been self hosting for years and bought it to support him. I like the style of writing and how he explains the concepts.

If you go with QNAP be careful with what you provide access to over the internet. QNAP seems to have security vulnerabilities quite often. It would probable best to only use a VPN to access any services/media on it.

I’ve been running TrueNAS core for years. I used to have my applications in Jails on TrueNAS. If you just want to start out learning I think using SCALE and keeping your apps within TrueNAS is a good way to go.

I believe SCALE uses docker for its apps so that should make it easy to migrate your data in the future if you pick another platform.