Usually there is no need to install golang on the server, just deploy and start the properly crosscompiled binary on the server preferably managed by something like systemd.
In general I can suggest traefik.io as reverse proxy, as it will also manage let’s encrypt certificate and renewal for you. Also it can dispatch on domain and path to your backend applications.
It’s hard to suggest anything to solve the conflicts though, as you haven’t even told what kind of conflicts you have.
My guess though is, that you have already some application listening on port 80 and/or 443. You need to configure that to listen somewhere else and put it behind the reverse proxy of your choice as well.