expect almost everyone to yell at you and make fun of you for being new basically because having a new player usually means the team loses. You may be extremly lucky and get someone willing to help you out, but that likely won't happen. Don't expect to have much fun for your first dozen games, but if you do manage to survive the initial period of not knowing what the hell to do, dota type games are probably the most enjoyable multiplayer games to play. 

as long as you have nice people playing with you it should be pretty fun even when you have no idea what you're doing. It's just that the community can get very nasty at people playing bad because of how necessary teamwork is to win. But once you learn to play, there is no better feeling in gaming than winning a close game of dota.

The game seems very user-unfriendly. Definitely a lot harder to get into than League of Legends. After trying it twice I didn't like it and went back to LoL.

Yeah. i got mine a week ago, still haven't had the time to see how much it differs from LoL. Haven't even played LoL actually.

I got my key last week and played and won three games so far.. Let me suggest that you try playing "Heroes of Newerth." It's currently free to play. Try it out and I assure you won't want to go back to DotA 2 or LoL.