Woolacombe has an enormous beach....the town itself isn't much. If your driver is flexible then you could go to a few other things.

-Braunton Burrows - a large sand dune area with good walking. Cold and a bit windy though.
-Lee Bay - A narrow little valley that leads down to a beach.

If you an get further away then there is a rather neat outdoor miniature railway at Blackmoor Gate, the Exmoor Valley Railway. It is about a mile long and takes 10minutes or so to go round, great if you love the smell of steam trains! I used to love it when I was 8

Nothing is groundbreaking or awesome which is about par for North Devon but better than nothing!