Dude, I went by myself three years ago and it was AWESOME, I played in tons of games and had a great time and had no problem hooking up with people to have dinner with or get a drink, just go already!
OK, not really, but I have gone with just one other person to Origins a bunch of times and its a blast.
I can tell you that based on last year my groups M/O is going to be hanging around the game-borrowing rooms from evening until late-night and playing a series of boardgames that look interesting. If nothing else feel free to contact me and you are more than welcome to join the party. I guarantee that all of us shower daily, don't cry when we roll bad, and are there to have a good time not destroy the hopes and dreams of those playing with us.
PM me if you like and I will front you some personal info.
If you are really worried about fitting in, you can always sign up for actual events. I have had most of my fun meeting new people, however, in pick up and demo games, not actual scheduled events. I have had less luck with those.
DS