First, make sure you can reach the pedals! Remember that the gas pedal is always the pedal furthest to the right, and the brake is always the pedal to its left. Then place your right foot on the brake and apply pressure, leaving your heel in a position where you can easily rotate and reach the gas pedal without moving your heel. You might need to adjust your seat to properly reach the pedals. In some vehicles, you can even move the pedals closer / further away from you.
Next adjust your steering wheel appropriately. In most vehicles, you can move them up, down, back, and forwards to fit your driving needs. Then place your hands on the steering wheel, paying mind to grip the wheel correctly. You may have heard the term “10 and 2” in reference to where to keep your hands on the steering wheel. Well, that is just plain WRONG! This is an outdated slogan that has been proved to be incorrect long ago.