Can someone please review my drone PCB?
Briefly,
1oz is usually referring to the copper weight and is a specification of weight per unit area. Or in other words the thickness of the copper. Standard weights are 0.5oz for fine pitch, 1oz standard, or 2oz for high current. It is not changed by the size of your board or the ground plane. 

Your layout has lots sharp edges and traces are much longer than they need to be. Definitely remove any angles less than 90. Eg under the crystal. Preferably remove 90 degree trace corners. 

A schematic would be useful to know what's going on in the circuit.