Hey leeroy,
I reckon the best advice is, to have a look at the OBR tracks. Really the very first time I rode a mountain bike (3years ago) at age 32, I rode OBR together with three other novices on ridgid (cheap) mountain bikes. Granted we fell off many times, but we had an absolute laugh. One of the best days I have ever had on a mountain bike. Thing is with any track that you do not know, take it easy until you get to know the tracks, and please respect the quiet neighbourhood, so keep the noise to a minimum and have a go. As for getting in the way of others, mate they all had to start of slowly, so don't be put off by that. After all it's about having fun.