How to put drywall over garage uneven concrete wall?
Usually when drywalling over masonry walls you install furring strips.  Furring strips are verital strips of wood to which you can attach the drywall (or plywood or whatever you want).  You can easily position and / or notch the furring strips so that the face of the strips comes out level.  You can use lumber as small as 1x2s, it's also common to use 2x4's.  There are also metal furring strips available.  

Heavier furring strips are better for attaching shelves etc.  Sometimes by the time it's all said and done, you're better off just framing a hollow wall in front of the masonry wall.  This way you can leave a little breathing room between the wall and the masonry, and you have a full stud depth for insulation, electrical, etc.