Santorini is so wonderful you can't go wrong.
I can recommend Iriana Cafe on the cliff side. Remvi also had a great sunset spot.
Tip!
Finding the famous blue domed church in Fira is not easy
Find the Mama Thira restaurant. Immediately to the left is a set of stairs. Walk to the top, then follow the signs.
The view is from an unfinished parking area on the right (you are circling back toward the sea, above and to the left of Mama Thira.).
Ah!mazing!