Off course there's the occasional retard that you just want to ... you know what I mean, but those will be everywhere.
I don't think it's hard to get accepted in the DOTA community, there are a few basic unwritten rules tho.
1. 90% of the people on the European server hate russian players, not because they are russian, but because a fair amount of them are infamous for raging, afking, and never speaking english.
So pretty much: Ur in an online game with 5 people? Speak English and be a nice person.
2. People will understand if you're new to the game, aslong as you communicate. If you ask ur teammates nicely what to do cause you're not as experienced you'd be surprised how much help you get. Same goes for when u screw up, which is obviously gonna happen if your new, people will understand, atleast most will.
3. Stay away from Carry-heroes until you get a basic understanding of the game and know all the heroes, there is NOTHING more annoying then an inexperienced player playing a Carry.
Tip from me:
Try starting with heroes like, Crystal maiden, Lich and Venomancer. They are pretty 'retard-proof' and any team lineup benefits from those heroes.