Accessing a server remotely using a domain

[Testkill 0]

Hello

Context:
I've spent the last few days trying to figure out a way how I can host my dedicated server. I now live in an appartment with a double nat situation (fun). I have full access to my own router but it's connected to a common router, thus I can't port forward. Figuring out a solution with the landlord is not an option. I've tried a lot of things already & got several working each with drawbacks. Cloudflare tunnel works perfectly (not having the below problem), except for the fact that you aren't allowed to stream.
Tailscale, ... etc isn't really "public".

Problem:
So i've went to look at VPN's, like this one, I bought a 3 day membership to test it out before comitting for 3 years.
I  got it working, except for the fact that I can't figure out a way to not have to specify a port. nginx isn't a solution neither from my understanding. You'd then also need a port for nginx. I want to be able to host multiple things on multiple ports and use subdomains to target. like thing1.mydomain.xyz.
Is this possible with airvpn? Are there other solutions that would work (that don't cost 200/y)
I've read a lot on this forum but can't find a exact/similar case most posts are about the forwarding itself. I've also searched on reddit a lot.
knowledge level: I'm finishing a embedded electronics degree, grasp on networking, but this is very new to me, especially the linux side.

I'd appreciate any advice.
 

Edited ... by Testkill

[Staff 9771]

9 hours ago, Testkill said:

I  got it working, except for the fact that I can't figure out a way to not have to specify a port. nginx isn't a solution neither from my understanding.

Hello!

Port specification is mandatory in Internet Protocol (IP). A port "is a logical construct that identifies a specific process or a type of network service. A port at the software level is identified for each transport protocol and address combination by the port number assigned to it. The most common transport protocols that use port numbers are the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP); those port numbers are 16-bit unsigned numbers." (WIkipedia)
https://en.wikipedia.org/wiki/Port_(computer_networking

You may get the illusion that URLs locating web sites don't need port specification, but it's only because  adding :80 and :443 if the port is omitted is a default behavior for HTTP and HTTPS. Now, remotely forwarding ports 80 and 443, and any other port lower than 2048, is not allowed in our service, so your client(s) must always add the destination port to reach your web site or any other service behind AirVPN.

Kind regards