It doesn't matter if you are interested in competing, judging, eating, or just watching. BBQ cookoffs are a great way to get involved in the world of BBQ.
As a newby, you could observe and ask questions of the experts. You may have gained enough confident that you want to start competing. It could be that you have already won your share of competitions, and would like to get into the judging.
Cookoffs can improve your technique, get your questions answered, and improve your private gatherings. Don't forget making new friends with your same interests, improving your recipes, and having a little fun.