In my experience there is usually a game forming in the lobby. Usually, half the players try gimmicky strategies based around wonders and not getting rushed, and they leave if anything bad happens. That said, the other 1-2 players might be good competition. It's fun and worth playing but don't expect too much.
I've also played some duels, and a 3v3 (props to sativa for invite), that were very challenging and quite fun. Basically, you need to find the good, reliable players and run games with them (without gimmicky quitters).
Third, you will find that multiplayer in general is much more brutal than single player. Generally, if your unit is vulnerable, it will die. People may double move, by shift clicking or moving near the end of the turn timer, then moving a 2nd time before you can react. Try not to lose workers, settlers, great people, or cities to this. Also, combat is kinda a clickfest of ranged attackers. Make sure you have enough of them to win this clickfest
Overall, I enjoy it, but it's not very well done.