It depends on what beach you want to go to. If you want to drive on the beach, try Daytona. It's N.E. of Universal. Figure about 1-1/2 hours from the time you leave to you end up on the beach. Cocoa is a similar beach, but you can't drive on it. It's not quite as commercialized as Daytona. It's due east on the Bee Line and takes right at an hour. Slightly S.E. is Melbourne Beach, same ocean, no driving on the beach. and less commercial yet. Of course, if you want to see the Atlantic with no buildings around at all, you can go to the Canaveral Natural Seashore. It's a federal park and is also east over in Titusville. It's sand undes and sea oats (don't pick them, they're protected).
The gulf is on the west coast. It's much more tranquil and reminds you more of old Florida. There's no beach driving on the west coast. You're more likelyy to collect seashells on that side. Anywhere from Clearwater south to Sarasota is nice. Figure about 1-1/2 to 2 hours to the actual beach.
Hope that helps ...