Chris,
Welcome to the Sun Coast!
The boat you're bringing down should be okay for the inshore waters of Sarasota Bay as long as you're careful. Just be aware that winds and T-storms can pop up quickly and make things dicey.
Yes, it's kinda/sorta common for folks with offshore boats to invite friends along to share the duties and expenses -- but you'll need to get known a bit. My suggestion would be to visit a local tackle shop in the area once you're settled.
Economy Tackle in Sarasota on US 41/Tamiami Trail is a good on, as is
Discount Tackle in Bradenton -- I'm sure there are more. Stop by, pick up a few tackle items that they recommend and ask if there is a local Saltwater Fishing Club that meets regularly.
Here in Tampa/St.Pete we have several clubs;
The Old Salts Fishing Club in St. Pete is the oldest in the area and they welcome new members.
The Golden Triangle Fishing Club is another, but it's in Tampa.
There area also two popular online fishing forums in our area: The Capt Mel Berman website;
http://www.capmel.com and the Florida Sportsman Magazine website and forum;
http://www.floridasportsman.com
Good luck and tightlines,
PB