Villa Agas is the perfect spot to stay in Santorini. It has the bus stop right at the front, near to bakeries, supermarkets and places to eat.
From here is a 15 walking to the heart of Fira, or you can rent a motorcycle or an ATV right there (strongly recommend) so you can visit all the beaches. If not, this place has a great pool where you can stay all day long if you want.