What are the dimensions of the parking apron?
The Apron Planning and Design Guidebook is used in the US. The goal was to provide a one stop shop for all the relevant information. The FAA maintains a list of standards.

Further, there is special CAD software for the design of airports. This includes the turn radius planning for a large number of aircraft.

Finally, because of the complexity and the large number of regulations there are companies, that specialize in airport planning and design.

Or you could always just wing it like the Germans and be ten years late and six times over budget and still incomplete ...