One thing I will tell all new players to do after joining the server. Is to complete the entire single player campaigns. Once you do that you will be better than a lot of the super new players we have.
Thats decent advice, it'll improve speed a bit, it'll teach some of the basics, so at least the non expansions is good.
The few games I tried to join people would automatically suspend me or ban me from their games, because I have 0 games, its pissin me off.
If they ask you "s9?" the answer is 30k, if they ask you "11?" the answer is 65k. Its like a protocol to see if your a noob or not. And if they don't want noobs in there game you'll be kicked. Knowing the answer to those questions gives you a better chance of not being booted.
Also, try ask to watch some games when you join, set your race to Human (Since 99% of people player Orc) and Ally up with everyone on the allies menu, and hide your peon but don't give them vision, and turn on allied victory.
If it's a Top vs Bottom game and your watching, then vision everyone for a moment so they know where you started, then unvision them then hide your peasant in a corner of the map. If you run your peasant to try hide it while vision is on, people will probably get mad at you, because they'll be able to see things like chop spots and stuff.
If you don't know some of your basics like walling in your base and setting chokepoints, if I see you online i'll show you. Or maybe someone like mouse will.