i used to live in HB.....haven't been back in awhile, but a few of the places that i used to frequent appear to still be around........
Wahoo's Fish Tacos on Main Street is always good.....they serve, well, fish tacos........while you're on Main Street, hit-up Jack's Surfboards just to look at all of the surf stuff they have.....
Cappy's Cafe is a good dive restaurant on HWY 1......technically in Newport Beach........excellent bloody marys......
Mutt Lynch's on Balboa Peninsula....great views......good bar food selection.....great breakfast.......and you can't go wrong with a schooner (or two) of beer.....
can't speak on behalf of the whale watching.....
as for the beach, the locals are very territorial about their waves.........if you're planning on venturing in the surf when the waves are good, you've been warned.....
i golfed a few times at Tustin Ranch Golf Club.......it's very nice......but it's about a 25 minute hike north.....
overall, HB is really about Main Street and chilling on the beach......