Nice to see a fellow Virginian on here! I'm from Staunton myself, but I occasionally travel to Richmond for Ravencon and would love to check out their magic shop! If you're interested in learning from someone out there, I believe they have a ring of the International Brotherhood of Magicians, and there may also be a Society of American Magicians out that way. See if you can look into those. Most groups will let you visit for a while before they start asking you to join the ring, so it's a good way to get out there and meet some potential performers/mentors.
As for the rest of your questions, I'm afraid my answer will be a bit daunting, but there is truth in it and it's not meant to discourage.
You've got a ways to go before you're going to be able to transition to professional performance. You may be able to get a small gig here and there, which is fine if you're ready for that, but professionals, by and large, are not terrified at the prospect of drawing up a contract.
You already know some of the obstacles in the way, but I'll start with the one you probably least want to hear: your age. Being 16 feels like being an adult when you're 16, but adults look at 16-year-olds and usually see children. When I tried to get into professional magic performance the first time I was about 19, and it was still hard to get taken seriously because I looked like a kid. The air of maturity and professionalism tends to come from life experience and is not easy to fake. What you wear isn't going to have a big impact, either. At 19 I was dressing business casual or suiting up and my magic went nowhere. Now that I'm 26 I usually go into public dressed as a pink wizard, and I'm having more success with magic and performance than I ever have. Many magicians will say "Be yourself and don't dress in a ridiculous costume," but acting a character and dressing outlandishly has done the opposite of slowing my magic down.
Experience is going to be your next challenge. Many professionals will tell you they worked the craft for 10, 20, or more years before even beginning the transition into professional performance. You'll want to learn a broad array of sleights, methods, props, and gimmicks and of all the stuff you'll learn, you'll only use a small percentage of the actual effects for performance because you want to boil performances (especially shows) down to your best and favorite magic. Most professionals I've met have a STRONG foundation in classic magic, a working knowledge of current magic, and enough know-how and experience to build and/or create their own props, gimmicks, and effects from the things they know.
My advice to you is to hone your craft. Rather than using the next few years trying to break into the professional market at a difficult time, continue practicing and learning so that when you're old enough for age to be less of a factor, you'll be the best magician you could be at that time. Focus on expanding your knowledge of magic, learning what works for you, and performing on a volunteer/part-time basis (street magic, people you know, talent shows and charity events, etc.). This will give you the experience you'll need in order to have the option of performing professionally later on. If you can get some gigs and you're comfortable doing them, go ahead and jump on it for the experience, but professional magic is going to be a seriously uphill battle where you are at this moment. By giving yourself some time to grow, you may be able to level the field.
Edit: Not sure who posted this, but do NOT offer to work for tips if you get a restaurant gig, even if your'e not asking for pay. If the manager has even a quarter of a brain in his head he won't hire you for fear of pissing off the waitstaff, and if he doesn't then YOU will piss off the waitstaff by cutting into their tips. If you're working a restaurant, either don't take tips or give your tips to the servers whose tables you're working. That seems harsh and unfair, but servers in Virginia (and many other states) work for 2.13 an hour and their tips are pretty much their whole income since that hourly pay usually gets eaten by taxes. As a professional performer, it is not good business to upset the working class, especially the staff in the places you perform.