and read back several pages. There is a tremendous amount of advice for guys just starting out, as well as for those who are younger. You are far from the only younger Newbie to find his way to the site.
My advice:
Get VIP here on TER if you have not already done so. You MUST be able to read reviews completely, and being able to PM others is a great help.
Get verified by a service like P411 or Date-Check. RS2K is big in the Chicago area as well. The idea of a verification site is that it is easier to give personal information out once to a site that many ladies rely upon to help verify that you are safe. It will also serve as a way to simplify reference checks with future dates.
VIP and verification site memberships are not free... but the investment is well, well worth it. I'd say essential!
Look here on the TER ad boards, on the verification site, etc... for ladies who advertise "Newbie Friendly" and for those who are OK with younger guys. They ARE there. Read their reviews, websites and everything else you can find, and choose who to reach out to first. With VIP you can PM reviewers to ask for advice, although be prepared as many can be reluctant to reply to Newbies with no board history or cred.
When you do reach out, remember that a well-written introduction and clear request are very, very important. Complete sentences and good grammar - not text-speak! No mention of money (you should already know her rates and expect to pay them) or sex/sex acts - maturity, not vulgarity! Make a specific request to meet, specify when and for how long, where, incall or outcall, etc.. Be prepared for her to ask for some additional information - you will need to decide what you are comfortable sharing, but she is free to decline if you choose not to share what she asks. Don't get angry or discouraged if the first one or two contacts don't work out - that happens, and is NOT worthy of a complaint or rant on the boards. Just move on, and keep trying until you find a match. It WILL happen, and you will have your first reference -and life in the hobby will get progressively easier.
As for some advice others have given about lying about your age... HELL NO!
Do things right, put your best foot forward, and over time you will do well.
Good luck