I'm just wondering, is there a reason why not many teens like me don't try to design sites? What I'm asking, being younger does it bar you from have important design aspects? For example maybe as a senior I'd end up taking some type of typography class etc.
Are there things that you just learn from life that you apply to design? Any insight is super helpful
Absolutely. Great ideas rarely come out of the blue. Life experiences, traveling, things that you hear can all contribute to an idea. I wouldn't say there's an age restriction.. if you do outstanding work and you can prove to clients that you did in fact do it and you have the communication skills to deal with them, why not?
I started to learn HTML when I was about 10 by playing around with Geocities and Angelfire

I'd always build from scratch though.
I'll tell you this from personal experience, I got a job as a creative when I was 15. Worked as the only guy in-house and I definitely learned a lot just from working. By the time I was about 19, I figured I knew enough and decided to try freelance because an ex-coworker referred a client to me.
I did the CSS/HTML and all for the site, I got paid, we were both happy. It felt so great I thought I could do it over and over again. My only problem was I didn't know what I was really worth and if I was even doing anything properly which is when I decided to go through school.
Probably the BEST decision I've ever made. Turns out I was doing it all wrong, from the way I was dealing with the client, paperwork, coding, everything. I'm actually ashamed that I did that website and that was only 1 year ago. I'm 20 now and come November when I graduate, I can guarantee you that I'm going to come out of school as a 125% better designer armed with the know-how on dealing with clients and doing work properly.
That's not to discourage you from actually going out there and trying it out but I'm just warning you of all the intricacies of the business side of doing freelance work.
It's very tough to get a job in the industry without any prior experience as well. Again, life plays a factor here, who do you know and how good is your work? You can have mediocre work but if you know how to pump your own tires and make yourself look awesome to potential clients, you'll get a job ahead of the guy who's got more skills than you but doesn't know how to market himself more often than not.