Main controls, throttle pedal, gear selector, ign on, start button, engine stop cable and two brake control sticks. It has a 4 speed auto in it, IIRC, make sure the brakes are set. The sticks should be pulled all the way back and locked with the buttons on the top of the handles. Make sure the trans is in neutral, engine stop cable pulled. Power on, and crank. After a few revolutions, push the stop cable in and hit the start button. If it is a good runner, it will fire immediately. Look at your oil pressure, if it is good, select reverse, watch your guide and release the brake by pulling back on both sticks and pushing the buttons and SLOWLY let the sticks move forward. REMEMBER, these are your brakes, the sticks can be hard to pull on to get good braking. Pulling back on the left brakes the left track, the front will pull left in fwd and rear pulls opposite in reverse, same for the right. Remember when backing, brake with the opposite stick that you need to move the track to, if the track needs to move to the right, pull on the left stick.
To kill it, stop the carrier, set the brakes, put in N, ign off and pull the shut off cable out.
Is it on a gooseneck or Landoll type of trailer?