Used to live on Juno Beach, lovely part of the world.
Never found lunch a problem in the area, as there’s usually a bistro or something in most places that’s still open. If not, stop before lunchtime and see what the boulangerie, fromagerie* and charcuterie can offer for a snack.
Oh, and do not be tempted with a snifter or three of Calvados over lunch. You’ll never get back on your bike.
The beach road is well worth a look, as you could take in pretty much all the scenic/historic spots en route. Once in Caen, the Rue de Bras has some lovely cafes and bars, a great place for people watching. Oh, and don’t forget to see the Baleine at Luc Sur Mer. They’re awfully proud of it. 😉
*Pont-l’Évêque for preference.