From an article on the CrossFit Games site, I think it applies whether you are new or experienced with CrossFit.
If you could give someone just getting into the sport a piece of advice, what would it be?
Be patient. Your fitness level is something that is going to generally take a long time to get to where you think you want it. And when you are there, you will want it higher.
Don’t define yourself by your numbers and your times. Define yourself by who you are and what you are about. CrossFit is something that you do, it is not who you are. That can help keep things in good perspective.
Finally, find your weaknesses, make friends with them, then beat them to death.