Multi-user issues

So me and my cousin are trying to make our own game through the multi-user option so that we can do a couple of things at once,at the same time.However after watching a couple of YT videos and tutorials the server which we want to be connected to and work together is not appearing to any one of us.We are both new in UE4 and dont understand a lot of stuff so we might be doing something wrong, but from what I can tell we followed all the instructions and done the same things exactly the same , and the server just wont appear for us , so we cant work together on our game.Can anyone help ? I would be SOOO thankfull.