The solo student pilot reported that he was on final approach for a full stop landing when he observed another airplane waiting for the active runway. He intentionally landed long to accommodate the traffic and then "made [the] decision to keep up speed" in order to exit the runway quickly. He misjudged his speed and the airplane departed the right side of the runway, continued across a taxiway, and then down an embankment before nosing over. He later reported that the wheel brakes were less effective because he had full flaps selected. Also, he had applied aft yoke inputs, which minimized the effectiveness of the nose wheel steering system.