There are super markets in all places. To buy food for several days the best place is Manacor:
Mercadona at the Plaza Ramon Llull offers everything you may need. From here it is a short distance to walk to downtown Manacor (restaurants, cafés and shops). There is a second, more remote Mercadona which is not recomendable due to circumstancious parking.
Hiper Centro, entering Manacor coming from Palma on the left hand side. A large supermarket that has everything.
In Agromart, next to Aldi at the main road, you buy mallorquinean groceries. Recommendable!
And now quickly some breakfast buns: