I would like to ask if it is possible to make a drawing into a mesh. That would be very helpful. It can be a 2d plane formed like a cube or something.
You can do this with a Grease Pencil sketch, it has a Convert to Geometry Routine.
However, the paths created with this take ALL the curve points of the Grease Pencil sketch into the new mesh, so this may not be a perfect solution.
Usually the closest you get to doing that is importing an svg file form a vectors graphis program (adove illustrator for instance). Then you'd turn that into a mesh. problem being that is very really messy and results into a ruined mesh with too many faces. Best option is to draw what you want to make, plug it in the background (hit "N" and look for the "background image" option", then use that as a reference. The grease pencil you are using, at least in Blender 2.79 is mainly use to leave notes to yourself or other operator.