This is how you make a paper airplane.
Make sure to crease all of your folds
Step 1: Get a Sheet of Paper
Orient the sheet upwards (like shown) as if it was in a folder.
Step 2: Label
Label the top left 1. Label the top right 2. Flip the sheet so the 1 and 2 are oriented at the top of the page, but just on the backside of it. Label the new top left 3 and the new top right 4.
Step 3: Fold in Half
Flip the sheet back over so 1 and 2 are facing up and are on the top of the sheet. Now fold the sheet in half the long way. After open the sheet back up so 1 and 2 is facing you on the top of the paper. The crease you see in the middle is the midline.
Step 4: Fold Corners
Fold 1 and 2 to the midline. You will see 3 and 4 near the midline as shown above.
Step 5: Fold Sides
Fold the sides (Highlighted Edges Above) to the midline.
Step 6: Fold Up
Fold on the midline upwards so that all previous folds are on the inside.
Step 7: Wings
Fold top of the sheet downwards (midline fold is at the bottom). Make sure that you fold parallel to the midline. The fold should be approximately 2/3's down the sheet. Flip and repeat on other side.
Step 8: Flaps
Fold approximately where the highlighted line is shown above on both sides.
Step 9: Finishing Step
Unfold wings so they are perpendicular to the handle. Then unfold the flaps so they are perpendicular to the wings. After you have done those two things you will have successfully created a paper airplane.