Welcome aboard (so to speak). There are a couple pretty active threads in "General Running Discussion" and a couple in "Newbie Cafe". You're welcome to post in any of them. It's a friendly crowd.
If you find yourself having aches and pains, try "The Med Tent". You'll get lots of advice on most issues and there are a couple very knowledgable people who check it regularly. But hopefully you won't need it.
Good luck on your first race! It's lots of fun.
Len