Our first Greek experience was on a cruise. We did not know what to expect or where to go so It gave us an opportunity to discover Greece get a feel for how it works and see some highlights. The cruise ship gave us a safe haven while we acclimatized to what Greece is like.
This was sufficient for us to know we wanted to come back for an in depth visit and we were able to prioritize where we wanted to visit on land and ferry hopping. We have been back to Greece many times in the last 22 years all on our own plans and itineraries.
Many people come to Greece and do island hopping by ferry. The choices are overwhelming but as you sift through the Forum you will begin to see several prominent places that the majority of visitors love.
Santorini and Mykonos seem to be the most talked about Islands. Personally my advice for first timers is to arrive in Athens and immediately fly to Santorini. As your first Greek experience the views are memorizing and unforgettable. Its a great place to get over jet lag. It is also very expensive. 3 nights is all my wallet can take. Mykonos markets itself as a high end destination with the same prices as Santorini but there are better choices just as pretty and at a third of the price.
My recommendation for choices from Santorini would be Naxos and or Paros. Both are great islands to compliment Santorini. and both are about 2.5 hours away by ferry. Each are much more authentic and you can easily spend a week on either of them. Yu will discover that Greece is best experienced slowly. Many people have only 2 weeks so the last 3 nights will be back in Athens and all its antiquities.
Milos is another popular island to pair with Santorini.
The other popular islands are Rhodes and Crete. Crete is amazing just a 2.5 hour ferry trip. It has Venetian era old towns in Chania and Rethymnon, antiquities, mountains and great beaches. Crete needs one to two weeks and you will just barley see a small portion of it.
If you narrow down your research to these islands I think you will not be so overwhelmed. You can narrow down to a few options. Then come back and tell us when you plan to travel, how long you have, what are your primary interests your budget and then we can give more precise information on the islands that interest you.
Knowing what I know now, I would not take the cruise, unless cruising is you passion.
For fun here are a few images of Santorini, Naxos and the city of Chania in Crete. Maybe you can find inspiration in these photos.
Santorini https://www.flickr.com/photos/stanbr54/albums/72157632154800782
Return to Chania 2022 https://www.flickr.com/photos/stanbr54/albums/72177720299646015
Around Naxos town 2022 https://www.flickr.com/photos/stanbr54/albums/72177720299959098
Back to Naxos 2022 https://www.flickr.com/photos/stanbr54/albums/72177720299940917