Ok, so sorry if you take offense to anything I just don't know how much you know about these little engines and wouldn't want to leave something out. Did you pull in the clutch when you applied the breaks? It isn't an auto trans but you can convert it if you want.
Did you set your idle screw? (it is the only little screw on the side of the carb) You do this by screwing it in all/most of the way and then running the bike. Pull in the clutch and you will here it rev. Unscrew the idle screw really slowly until the engine dies. Screw it back in about one half to one full rotation and the idle screw is set. (Some people might say to put it lower like 1/4 but then little things like an uneven carb or being colder then normal could affect your idle) If you already knew all this stuff just say so and add a little more detail and i'm sure the others and I will get you on the road soon