How to create path and road in blank area?

I have a blank area, there is only one building here, I want to design a town in this area for my university project. I need to define roads ( there are 3 roads which are located in this area.) and also I have to define the hight of building according to sunlight in order to achieve climate comfort in the roads and paths.
Is there anyone how can help me?
I am looking forward to using your fruitful tips.