Adding people to your 3d renderings can be one of the hardest things to do while still maintaining photorealism. 3d people generally don't hold up close to the camera, and 2d people have a difficult time blending into your scene properly, because you can't control their lighting conditions easily.
This latest video offering of mine offers some great tips and tricks for getting those 2d people to look just right! Of course, this is just one lecture of a larger course, namely Advanced Architectural Exteriors (A PRO course for learnArchViz.com found here).
Also, if you wan't to get the files and follow along, you can find those here.
Unfortunately, I can't just give you the people, because I don't own them, but you can check out the site where I got them, gobotree.com. It is a great resource that I recommend to everyone.
Enjoy the video: