@Parsons has some great suggestions to get started in your search.
For instance, Charleston has a wide open harbor with some shallow water but you can avoid those and sail the harbor or out to the ocean. Some commerical traffic to be careful of but not too bad. Beautiful city with the biggest marina right at the edge of town. Still a little walk or uber/cab to the main part of town though. Google is your friend. There is at least one boatyard for work when you need it. Marine growth on the bottom will require periodic in water cleaning if you want to have something other than a "dock queen." Charleston is right on the ICW. If you are retired military, Charleston has Joint Base Charleston.
Beaufort SC (Port Royal Sound) has a channel with some breakers on one side but no breakwater on the entrance to the sound so you don't get the breaking waves in the channel like at some harbor entrances (see St Augustine below). Port Royal Sound is wide open and great for day sailing and you can reach the ocean from Beaufort marinas in about 2 hours. All three marina's are right on the ICW and there is a good boat yard (Marsh Harbor) too. The Downtown Safe Harbor Marinia is right downtown with a 1 minute walk to the historic Bay Street. Think of the Beaufort as a "mini Charleston" with Spanish Moss, huge live oaks and multiple places to eat steps away. There is a swing bridge going North on the ICW and a fixed bridge with 65 ft clearance going south, which you have to transit to get to the sound to sail. Be aware that 65 foot clearance is a Mean High Water, which means that some high tides that are above the "mean" you have less than 65 feet clearance and may have to time your passage there. (I have to do that with my 40.5) Beaufort is just north of the FL-GA line which is the point where most insurance companys ding you if you are going to be ther during Hurricane Season. I don't think the marinas require you to vacate during a Hurricane. There is also a marina on Dawtaw Island. Bottom cleaning periodically will be required here too. There are two military bases in Beaufort (Parris Island and MCAS Beaufort plus the Haval Hospital Beaufort)
I love St. Augustine but trying to get through the breakwater with opposing current and wind can be a harrowing experience
. I've nearly broached a 45 foot sailboat there. Had to go back out and wait about 3 hours to try again and still "surfed in" a lot more than I like. It was downright scary.
Cost of living is pretty low in Beaufort and probably in Charleston (as long as you are not trying to buy a house).