Here are some useful links to get you started properly.
First and foremost, if you haven't done so already, give our Community Guidelines a read. It covers how to act on the forums, when racing in an event, freeroam, and everything in between.
After you've done that, it's time to pick up that promotion, so you won't be kicked when the next purge comes along. You can find all information in this thread. (Remember to visit the forums every now and then to stay informed should we do a Representative purge.)
When eligible, you can find all NoDo approved events on the Events Board. Just pick the sub-board for your platform, and join in on the fun!
If you have any questions about specific GTA racing techniques, car choices, or anything in between, I would suggest checking out the Guide to Racing in GTA Online. One of our members (Raptor_X_) has put together a complete guide which has plenty of useful information on racing in GTA for all different levels of racers.
You also want to consider joining one of our live chat clients. Slack (text) and/or TeamSpeak3 (voice) to get even more involved in the community as a whole.
If you ever have any other questions, issues or concerns, feel free to send me or a Commissioner a message.