

There is no way to be 100% sure, but:
I can and do self host, but I’m not willing to provide these services for free. I don’t want to be responsible for other peoples passwords or family photos.
Thats where good, privacy-respecting services come into play. Instead of hosting for my neighbours, I would recommend mailbox.org, bitwarden, ente or a hosted nextcloud.
The blog post contains an interesting tineline. Apparently, the first fix was not sufficient. So if you have updated Vaultwaren before November 18, update it again.
Copy of the timeline:
Your challenge is that you need a loadbalancer. By hosting the loadbalancer yourself (e.g. on a VPS), you could also host your websites directly there…
My approach would be DNS-based. You can have multiple DNS A records, and the client picks one of them. With a little script you could remove one of the A Records of that server goes down. This way, you wouldn’t need a central hardware.
For a start, try hosting something in your own home. A raspberry or an older PC or laptop should be enough.
My first projects were a print server (so I can print via wifi) and a file server. Try to find something that is useful for you.
Only start hosting on the internet when you’ve learned the basics and have more experience.
I’m currently comparing Authentik and Authelia. For me, Authentik was extremely easy to get into. Authelia with its text-based configuration is clearly not as easy for beginners.