Outside of the main town of St Ives there isn’t much to be had en route and you may find you need to head inland a mile or two to reach a village. I can recommend the Tinners Arms in Zennor (St Senara’s Church is worth a visit too) for a good cider and the cream teas at Rosemergy Barn (summer only). There are convenience stores in Sennen (and a chip shop!) and some very touristy shops at Land’s End, where you may be able to pick up some water, as well as a couple of cafes in Porthcurno. For any more than that you’ll need to head inland.