How can I sort my photos?

I bought my first macbook today from a friend, they'd only had it a month and decided that they liked windows better and so they're switching back.

I'm trying to set it up and transfer all my photos from my external hard drive to this new computer but i can't seen to find a way to organise the photos in a way that's convenient. I really i would like smaller sub-folders within a bigger folders but when i try and do this in the "Finder" app, all the photos move from the folders i transferred them in to an unorganised mess!

I'm losing my sanity over this, please help!