i don’t understand how i connect the pc to the domain.
Yeah, that’s the part where I think there’s some misunderstanding. You don’t “connect” the server to your domain. Instead, there is a Nameserver (most run by your registrar, GoDaddy) that hosts a list of DNS records, that you can edit, which point to IPs. So you need to edit those to point to your public IP (or set up stuff like DynDNS if your IP isn’t static) and once that’s doneand the port forwarding is also set up properly in the Fritz!Box you should be able to connect.
That said, what’s wrong with VPN? Particularly if you’re using Wireguard VPN, which was recently added to Fritz!Box, there shouldn’t be any performance differences. Plus, it would be safer than exposing services to the whole internet, doubly so if you’re not a networking expert.