You're 14, 5'3" tall and you bought an 85 cc bike?
Start looking for a replacement now, that bike is too small for you. It can be good to learn on, but when you start trying to go fast it may actually be dangerous for you.
The basic problem is that the bike was designed for a much smaller rider. Your center of gravity is too high, and with the short wheel base you are just asking for a short flight over the handlebars.
Weight is also an issue. I would be surprised if the bike's suspension can be adjusted properly for someone your size.
Rod