Rotate your wheel so the air valve is easily accessible. Unscrew the valve cap and set it aside.
Fit the pump's hose nozzle over the valve. Push the nozzle head down over the valve and lock it into place by pulling up on the small lever. If your valve is a Presta type (metal with a small screw at the top), fit an adapter into the hose nozzle first.
Stand over the pump, using your feet to steady its foundation plate. Grip the pump handle and inflate to the recommended PSI rating, located on the sidewalls of your tires. Use the pump's gauge as a reference.
Remove the nozzle by pushing the lever down and pulling the head away from the valve. Screw the valve cap back into place.
Repeat the above steps for your other tire if necessary.