If you decide to not got the YunoHost route, I like the way this guide did reverse proxies with Caddy: https://github.com/DoTheEvo/selfhosted-apps-docker.

I think it’s cool you’re trying to find ways to get into this. If the goal is to learn, why not deploy the services on your laptop? They won’t be available when the computer is off of course, but you would still get the full experience. Even a low-spec laptop will be better than a cheap VPS.

As others said, both Firefly III and Actual Budget do not support stocks. I wish they did, but I guess I’ll have to stick with GnuCash + Metabase for now.