The warp is probably "Washout" When you build the other wing panel, it should also warp with the wingtip up at the trailing edge the same amount.

Washout is a purposeful warp which reduces the angle of attack out near the wingtips, helpng to prevent "tip-stall." Tip-stall makes a plane fall off on one side and spin, which is very bad when flying low and slow, such as when learning to take-off or land.

The warp does reduce aerobatic capability, making a tight spin difficult, and imparing some other maneuvers which depend on stallng a wingtip to get the proper snapy response. However, it makes the plane more stable, and easier for beginning flyers.