To break the tree, press "f" key until it vanishes fully. To jump, press the space bar. To move, use the arrow keys. (up=forward, down=backward, left=go left, right=go right.) Please Note: the crosshairs (the 2 intersecting lines in the center of the screen) must be on the tree to break the tree.
Special thanks to McGuy, It was a YouTube tutorial of his that I followed.