Feral I am a bit like you.
On one hand the social aspect is really intriguing. On another hand I'm terrified of it.
I've tried out clubs before and enjoyed it but I much prefer to run alone. I like to look at the scenery, be in my own thoughts and most of all, run my own pace.
I take part in races for two reasons:
I am competitive so I try to run a good time by keeping up with others.
I want to go for what I fear the most which is talking to other people. I enjoy it once it happens... But I'm a bit of a social outcast anyway and terrified of masses. But in races, you can talk to like minded people.
And if you choose so, you don't have to speak to anyone. Put earphones on. If you dont like music, just put it on so it looks like you're listening to music. Nobody will bother you then.