That's a great question! I have no idea. I'm not sure we've ever actually calculated that.
The mean score on the real test is about 550. So you're above average on that count!
It is possible that your score is a bit inflated because you skipped IR and essay. (Or it might not be—impossible to tell, but something to consider, that's all.)
Anecdotally, I'll say that a 590/600 with minimal study so far is a good starting point. If you are looking for a high 600s or 700 type of score, you are in a reasonable position. With dedication and work, of course.
The important thing to get out of your first test: a good sense of your strengths and weaknesses. Use that to help you priorize your studies as you continue to move through your studies.
Good luck! Check in and let us know how it's going!