Stick to it and get help from the moderators when you can!! The more you understand the site, the more easier to move around!! Great job in starting your goal!!!
Definitely just keep checking the site and responding to people. The more you talk about your plans and goals and help other people with theirs, the more you will be motivated to stick to your plans and exercise. I'm fairly new here too and so far I have found nothing but great, supportive people. Also, you can't type and eat, so the more I type, the less I eat! Double bonus!
Post here every day! You will get plenty of encouragement.
Words of encouragement: just think about how great you will look when you hit your goal weight. Buy a pair of pants that are a size or two too small and imagine yourself wearing them. Think about how nice your fit, lean body will look and all the attention you will get... AND even though you are not severely overweight, once you are not overweight at all, you WILL be healthier, even if it's just a few minor changes.