Why when clicking on numpad_0 or only 0 i don't see anything with the camera? The camera is viewing the city.
I scaled the camera made it bigger.



Then i click on numpad_0 and see



But if i will make a new project with only the cube in the start and will click the numpad_0 it will lock and show the cube.

Why it's not showing the city ?
This is due to your far clip setting under: Camera Tab -> Lens -> Clipping -> Far.

Adjust that to a ludicrous number and you should see your buildings, but I'd suggest adjusting your scenes scale since this gigantic scale may cause other problems down the lane.