Driving tips - newbie here

You probably have "Grade braking" in your transmission, touch the brakes and the transmission downshifts to use the engine compression to assist in braking. To stop the grade braking you have to press the throttle just a little and it should come out of grade braking. But then you need to use the brake pedal again because you are definetly going to fast down the mountain. You can also manually downshift the transmission to find the right gear to slow you down without letting the RPM's get to high. It would help if you posted what engine and transmission you have, and you will get more detailed instructions on how to operate that transmission. Always slow down before you start going down a mountain and then engage your grade braking.