Using the Pedal Thrasher 3 is easy. First, adjust the seat to a comfortable height. Then, check the tire pressure before each ride to ensure good traction. When riding, use the Shimano Tourney 3x8 speed drivetrain to shift gears according to the terrain. For uphill, use lower gears; for downhill or flat roads, higher gears. Remember to use the mechanical disk brakes to slow down or stop safely. As for maintenance, after every few rides, clean the bike with a soft cloth and mild soap. Keep the chain lubricated regularly to ensure smooth gear - shifting. Check the brakes and tires for wear and tear often. If you notice any issues, get them fixed by a professional bike mechanic right away.