Disney doesn't allow off siters.... this is not DL. WDW has never allowed those dealers on property. They don't even allow direct transportation to US/IOA. Now SW started back in the 70's - there is a Lynx bus for this. to get to US/IOA you would need a rental car, taxi, shuttle. there is no publix bus to take you.
there is a beach at CBR. You will be walking along it each day - going to the food court....
This is one of the unfortunate things about staying at a Disney resort. They can provide plenty of help when you want to enjoy other Disney activities, restaurants, tours, etc - anything that will earn more of your money. But don't expect help from them for ANYTHING external to Disney's system. Sorry.
Offsite resorts will usually offer assistance with dining reservations, tours, parks and attractions at a wide variety of venues in the region. Some do provide access for their guests to daytrips to the coast for ocean beaches, deep-water or sport fishing excursions, casino boat rides and the like. I know I've seen them listed at some timeshare resorts but I cannot recall offhand which ones or the tour operators who offer them.
An online search for "Orlando beach tour" turned up some pricy options that anyone can book themselves. But my recommendation is to rent a car for the day (you can do this at several onsite Disney hotels). Map out a plan online for where you want to go and do it yourself. The major beaches are easy to find and public parking & changing facilities are well-marked - Daytona & Cocoa on the Atlantic side for bigger waves and Clearwater on the Gulf side for warmer, calmer, bluer waters. HTH.