How to play online with friends?

I just started playing, and unfortunately, I don’t have the money to buy it on Steam, so I downloaded it through Hydra, using Online.fix.

We looked for several tutorials on how to play online but couldn’t find one that helped us. My friend even invites me through Steam, but it just keeps loading a message saying, "Retrieving server information" indefinitely. I think we're doing something wrong because we haven't been able to play yet.

Can anyone help us?