I noticed a couple other threads posted by you. I will just reply to this one with what I read in the others. So you want a cheap drone to capture aerial footage of your city. You also asked if you need any sort of training.
I believe you need a license to use a drone for commercial use. So if you plan to make money, or use it for something that will lead to money, you need the training.
As far as getting a cheap one, I would check out Banggood.com first.