In terms getting girls there should be a market in each part of town go there and buy the girls in order there's also the exclusive shop if you have the exclusive version in the first map. each girl you buy from any market depending on how far you are corresponds with the apartment in each map
Edit: forgot to mention that each map has a different price range 1st range 500-around 900 ,2nd is in the thousand and up 3rd I ain't exactly sure since I ain't going to get that far.