Cocoa Beach is the best beach within 1 hour of Orlando Florida or Walt Disney World Resort. There are several attractions at at nearby Cocoa Beach and it makes a great day trip. Need supplies? No worries as the Ron Jon's Surf Shop basically great you upon arrival. The Cocoa Beach pier and area await.
The closest beach is Cocoa Beach and normally the traffic to it is not overbearing. Downtown Orlando and Walt Disney World have about the same drive time to this barrier island beach town and many make this journey
On the north end of Cocoa Beach you will find the Kennedy Space Center Port Canaveral and Cape Canaveral National Seashore. On the west side of the barrier island is the Indian River Lagoon but trust me, the best beaches are on the Atlantic coast side and the water is brownish in the Indian River. Believe it or not Orlando Beach is immediately south. So technically there is no doubt that Cocoa beach is the closest beach to Orlando. Yes, Central Florida has two Orlandos and an Orlando Cocoa Beach border. Further to the south you will find Vero Beach.
Daytona Beach is to the north on Interstate-4. The drive is usually easy but just a little longer. You will of course find the Daytona International Speedway, the Daytona Beach Pier and the Daytona Beach Waterpark which is beside the pier. This is a great beach suitable for boogie boarding, paddle boarding all about an hour away This is a beautiful beach to cap off any Orlando vacation with soft sand dunes and it is a family friendly beach. New Smyrna Beach is to the south.
If you are a little more flexible and are up for discovery head west to Clearwater beach Florida. I will warn you it is a little further away. But like downtown Orlando it is worth seeing and it has more than you suspect. Gulf Coast aka gulf beaches typically have white sand we all envision.
The top beaches, Clearwater Beach and St Pete Beach are the best beaches near Orlando period. Deep sea fishing, soft white sand, beach breaks and better towns and hotels adjacent to them. Visit here, you may never visit the theme parks in Orlando again.