Conversations at a yard party.

I went to a neighbor's yard party this past weekend. It was interesting.  I went with my parents and it was all awkward.  I felt like I was looking people in the eye too much. I don't know how to talk to people so I feel like I'm either staring at them or they think I'm just not paying attention at all.  So I don't know a lot of people at this party and I end up next to this guy R.  He starts asking me where I'm from [2 houses up the street] what I'm doing and what I want to be doing in the future.  He almost barks his questions but he isn't trying to be rude.  I feel like he doesn't know quite how to talk to people either but is unaware of this and he keeps shooting questions at me like shotgun blasts. Now it's something about my dogs and then it's about the back way to route 101.

I somehow got into a conversation with three random people for about an hour and I have no idea of what we talked about.  It's a little better than one on one conversations but still confusing for me, because I feel like I'm supposed to know who is going to make a comment to me when and I really have no idea whatsoever. I feel like I'm constantly on guard, looking for the next pass or something.

I ended up going on a little tour of the house, which I found odd but amusing.  Then somehow I got drafted to sing with some guys who were playing guitar which was amusing as well.  All of our musical tastes almost overlapped, so we took forever trying to find songs that we could do together.  By that time I'd had a few drinks and decided it was probably a good time to go home.
I joined this softball league over a month ago and now it is starting soon, so there was a meeting/preparty thing that I needed to go to where I went to meet my teamates.  Only four of us out of... nine or ten or twelve, not really sure, showed up.  And again, I was all weirded out by the conversation thing.
Am I staring?
Am I looking at them enough?
Do I seem like a spaz?  
...well, I don't think I offended anyone and I usually consider that a success.

My mood is ok right now.  That's another thing.  I keep cycling around and stuff so it's like I figure I can't be too bad.  By the time I even consider maybe doing something, I start to feel somewhat normal again.