A community to help people learn, install, set up or troubleshoot their home network equipment and solutions.
Your network has a public IP address, your computer does not. You can either tell your router to send any requests to a certain port to your computers internal ip address or you can set up a virtual private network for your friends to connect to.
I would definitely recommend the virtual private network route as it is much more secure and safe than opening a port on your router. There are many guides online about how to do this part
When you say "I proceed to port forward", can you describe what you are doing and on what device? Your router needs to have port forwarding set on it, so you forward a specific port to the internal IP of your server (open cmd prompt on your server and type 'ip config' and it will give you the internal IP, usually starting 192.168). If you want this external connection to work more than just the one time, then make sure the server has a reserved IP on your router too.
Likely your router does not support NAT loopback.
Thus, you will not be able to connect to your public IP in the port forwarded from a device that is behind your own router.
And that is correct that all devices on your local network will show is having the same public IPv4 that is what a net router does.
Use IPv6.
Update: I called them and they where able to reroute my public ip address. They had accidentally misconfigured it when they where setting up fiber internet.
Think of it like an address on an office building. The post office delivers all of the mail to 123 Candy Cane Lane. The name on the letter doesn't matter to the mailman, they have no clue where Fred Smith's office is located, and they aren't allowed in the building anyway even if they did. The receptionist at the office takes all of the mail and passes it along to the correct person based on the name. If they've been told where Fred Smith's office is located, they deliver it. If not, they assume Fred Smith doesn't work there and they either reject it or just throw it in the trash.
Your ISP is the mailman, your gateway/router is the receptionist. The name on the envelope is like the port number. As long as you configured the router to take traffic meant for port 25565 (default for Minecraft server) and forward it to the INTERNAL IP address of your minecraft server, it should work if your friend connects to your PUBLIC IP address.
Depending on your ISP, you could be in a double-NAT situation, which basically means there's another receptionist in between, and you have no way to tell that receptionist who is who, all they do is reject all mail unless they're told ahead of time to expect something in return of what you sent out. If that's the situation you're in, you won't be able to run a server at all without a VPN that allows port forwarding, or some other sort of method to proxy the connection.