Need Help with Scale for first try at Environment Modeling


So I would like to try some Environment Modeling. I want to do Like a Cyberpunk type city street.

I understand the reference stuff blocking out etc ie the pipeline. However since I live in a very rural type area I have no feel for scale of big city buildings.

How do I come up with a realistic scale when doing city Buildings?

From my reference the smaller buildings have people on the streets I can use them to get a rough building height but what about the base length or even heights of skyscrapers etc?