Hi everybody !
I really need your help because i need to run a server for a cup but i got a big problem !

When i start the server, the console say : Warning ! You seem to be on a private network. Unless you have configured your NAT, other players on internet will not be able to join in !

I try to connect only me, and either when it's me, i can't enter on it !

So if you guys please can help me, it's gonna be really apreciated !

Can others connect? If so: either use a loopback adapter to connect to your server "the normal way," or just join the server using LAN yourself, locally.
If others can not connect too, your computer's firewall is probably blocking it (and probably your routers too).