If I take 2 sheets of paper and drop them at the same time, how can I make one of them hit the ground before..

make it a pointed rocket by paper no. 2, it will cut through the air and will come to earth faster. but in the absence of air both will come to the earth at the same time.

If you are not concerned which of the two hits the ground first, then one of them always will. If you want paper #2 to hit first, crumple it more tightly than paper #1 to give it less air resistance, and if you want #1 to hit first crumple #2 less tightly.

If you drop paper 2 on edge so there is no wind resistance it will hit first. A slight fold to keep it straight will help.

Compress #1 to make a ball. Cut half the length of #2 and fold the two flaps in opposite direction. When both fall, #1 will hit the ground earlier and #2 will keep rotating while falling and will hit the ground slowly.

fold the the second sheet so that it traps air and make it act like a parachute. fold the second sheet in a way that makes it interact with air flow. fold the second sheet into a sort of rotor so that it has to spin as it falls down.

The crumpled piece of paper will reach the ground b4 the unmolested piece of paper will. I think its the surface area that determines how fast the two objects will fall. It could also be the density.