To start small setup a static website behind nginx. This requires you to create a basic website or copy a template, it goes somewhere in your filesystem, in linux /var/www is common. Once you have that, setup the nginx service and point it to that location. You can do this locally then expose it to the net or put on a VPS. Here is a dead simple guide presuming you have a remote server: https://dev.to/starcc/how-to-deploy-a-simple-website-with-nginx-a-comically-easy-guide-202g

Once you have that covered, ensure you know how to setup ssh keys and such, then install, configure, and run services. From there, most things are easy outside of overly complicated configurations.

Mullvad doesn’t have port forwarding, so that’s going to be a factor.

The primary reason free VPNs/proxies are not recommended is due to the high amount of abuse that flows through them. As a sysop, it’s just easier to blanket ban all those IPs.

I have ethical concerns with your use of RiseUp as well. They are trying to offer a useful service to people on a donation basis, and you are funnelling a large amount of traffic through them.