For example I'm a local florist in Miami If I gonna target my adword campaign to Miamy city only will it help to improve my SEP for related keywords (florist miami etc.)?
no, of course not. All of my most successful websites in its targeted keywords (get the first rank) never had any experience with PPC.
So how do you know that it's no influence if you don't have any experience in PPC with your web sites?