Note: ADISC does NOT allow personal ads. This includes "looking for ____" or "anyone in ____" type introduction posts. To write a good introduction, focus on explaining who you are, NOT what you are looking for. The goal should be to help other people get to know you a bit.
I had a hard time coming up with things to talk about - still do! Another thing I found that helps is to start reading all the threads that interest you and join in. Maybe one of them will help you think of something to write about.