But I am getting nowhere

I actually had 2 different things happen on two different attempts couple of days a part.
First I got a multiplayer session going but as soon as I end up joining the session it would timeout and end.
On second try, whenever I was trying to create a multiplayer session, atmosphir would load to 99% and then just hang
there forever.
What am I missing? I don't play any multiplayer games so I feel a bit lost. Your help is much appreciated.
If you know anyone who recorded a video tutorial on starting a multiplayer game, please kindly point me to it.
Thank you.