As Sean said, in STL Region we run a Novice Championship. So, you'll run in your normal class (and be included in that Class Championship), but you'll also be included in the Novice Championship, which is index-based on the PAX index numbers for 2016.
For eligibility, you're considered a Novice if, prior to the start of the year, you've done 5 or less autocross events. So, with 2 on your resume, you're fine there.
I believe on Motorsportreg when you sign up, there is a checkbox you can mark to alert us you're a Novice. Also, at the event when you check-in, mention that you are a Novice and we'll add you to the Novice Championship list.
Any other questions, let us know or grab someone to chat with at the event. We look forward to seeing you out there!