First time Greece trip: Santorini, Mykonos, Athens, Meteora/Delphi

Hi, I’m traveling to Greece in July for 14 days by myself.

1. 4 nights in Santorini, staying near Perivolos Beach (no excursions scheduled yet. Thinking about a day cruise of Santorni which I can book through my hotel.
   1. 3 nights in Mykonos with a trip to Delos. I am close enough to Mykonos town to go on my own and Little Venice also.
   2. 3 nights in Athens with hop on hop off bus ticket for 2 Days which will take me to the Acropolis etc. My hotel is a 10 minute walk from Acropolis.
   3. Two day tour of Meteora and Delphi

Beaches are definitely on the itinerary!

Is there anything that you can suggest that I could add...day trips, other sights that anyone can suggest?