Easy Itinerary (hopefully)

I suspect most people here are going to recommend you start in the islands first then work back to Athens being that you want to be on the mainland before your flight home anyway and getting over jetlag is more pleasant on a Greek island :) So land in Athens and then immediately fly to Naxos and then ferry back to Athens.

That's what I did. I flew to Santorini after landing in Athens then ferried to Naxos and finally to Athens.

I spent 1 night in Delphi and was very glad I went. I think it's worth it IMO.

That seems like a good idea.
Fly straight to Naxos -3 nights
Ferry to Paros - 3 nights

Ferry to Athens - 1 night
Delphi - 2 nights (or is 1 enough)
Back to Athens - 3 nights

The problem with flying directly to the islands directly after landing at the Athens airport is your originating flight from the US might be delayed causing you to miss your flight to whichever island your choose. I think your original plan to spend your first nights in Athens is the better plan. I would give Athens 3 nights. I have not been to Paros or Naxos so I can’t comment on those. Another suggestion after returning to Athens airport from the island of choice is to pick up your rental car at the airport and then drive to Delphi. I would spend two nights at Delphi if you cannot get there early enough from the Athens airport to spend at least half a day there.

I strongly recommend that you fly from Paros to Athens, and then go directly to Delphi from the Athens Airport. Otherwise, you are wasting too much time going into Athens twice. You could rent a car at the Athens Airport and then drive to Delphi. When you return, drop off your rental car at the airport and take a taxi to your hotel in Athens.

If you really don't want to drive, then how are you getting to Delphi? Tour group? Private driver? Public transportation? You could arrange to have a private driver pick you up at the airport. Or look into public transportation. You need to check airline schedules, bus schedules and train schedules to see if this works out. Personally, I think driving in Greece is easy, which is what we did in May 2022.

I also recommend that you fly from your home airport directly to Naxos on the same ticket, if the cost is not outrageous. You will most likely have to change planes somewhere in Europe. But the advantage to this is that you don't have to worry about your luggage until you arrive in Naxos. And the airline is responsible for putting you on the next available flight to Naxos if you miss your connecting flight. Last year we flew Boston/Zurich/Santorini all on one ticket. Very easy!

A possible itinerary:

Naxos - 3 or 4 nights nights
Paros - 3 nights
Fly to Athens Airport and try to avoid overnighting in Athens
Delphi - 2 nights (I think 1 night would be fine if you drive, but you might need 2 nights if you depend on public transportation)
Athens - 4 nights

And exactly how many nights do you have on the ground?

I have been to Naxos which I love but we did not visit Paros so I don't know if the 2 are similar. If you decide on a different island, just make sure it is easy to get to from Naxos. You don't want to waste time traveling. I think staying in the Cyclades would be the easiest.

Some great suggestions, Thank you all so much!
I had thought to take public transportation to Delphi, but now I'm thinking it might be too much. I hate to do this, but maybe skipping it this trip and focusing more on the islands will relieve some some added stress.
I probably will have about 13 nights... flight isn't booked yet, want to get more of an idea first. So maybe if I omit Delphi I can add another island (or closer mainland option to Athens)

If you are concerned about driving to Delphi, it is quite easy from the airport as you will be on a major highway skirting Athens and then a slightly twisting mountain road to Delphi. You can take that portion slowly. We found it no different or more difficult driving in Greece than driving in the US and we did it before GPS just using maps.

Don't try to do everything, see everything in such a short time.

I would not add Delphi. 2 weeks is the right average time for visiting (and enjoying) Athens + two islands.

Keep at least 4 nights for each island. 4 nights is only 3 full days, it’s not much. And be aware that moving from one island to another will take you a good part of the day.

"how many nights is really needed in Athens. I always give major
cities more time"

It all depends on what you want to do. Basic visits (museums, archaeological sites) require 2.5 to 3 days.
But Athens is not just museums and sites, with its close suburbs it's a city of 8 million inhabitants (6 times more than Manhattan).
You could stay in Athens 10 days or more, you would still find something to do.

"Are Naxos and Paros to be similar?

Paros and Naxos are similar and different at the same time, Naxos is larger and more mountainous, anyway no island is similar to the others in Greece, the inhabitants, the atmosphere, the culture, the landscapes, the food are different.

“Is there maybe an island that I would be missing?”

In the Cyclades, apart from Mykonos and Santorini, Paros and Naxos are the two most touristy islands, and yes, you are missing 18 other islands. Most are only accessible by ferry.

That being said I've given up trying to understand why 95% of the travelers who come to Rick Steeves' forums want to go to Paros and Naxos. (apart from Mykonos, Santorini and Crete). because I have always met North American travelers on all the Greek islands, and no less on other islands than on Naxos and Paros.

It's a big mystery to me! :-))

Thank you JoLui for your very thorough response. I think I'm going to take your advice on this one.
As for your comment about Naxos and Paros, I have to say, the reason I picked these placed is because they seemed to be the easiest destination to get to from Athens. While looking absolutely gorgeous.
Unfortunately social media has really made Mykonos and Santorini look like an absolute nightmare to visit. They've done the same with Amalfi Coast and Cinque Terra. And I know you cant believe what you see on social media, but when you see crazy pictures of thousands of tourists walking on top of each, you start to believe it. lol. So I'm always open to suggestions and will definitely do more research on the islands before finalizing anything.

Since your initial idea was to stay a few days in Athens and then go to Paros or Naxos by Ferry, you could also take a ferry to Serifos, Sifnos, Kythnos, Kimolos, Andros or Tinos. All these islands are less than 3h30 from the ports of Piraeus or Rafina.

Sifnos for example is, in the opinion of many people, more gorgeous than Paros and Naxos.
It's also the first Cycladic island that I visited (before the internet and cellphones) and more than thirty years later, it hasn't changed much.

https://sifnos.gr/en/sifnos/

Sifnos in May or June over the years:

https://photos.app.goo.gl/kHEMHyQe24eUHtj88

You plan to travel in April. While this has its advantages in terms of prices and crowds, but note that in the islands before roughly mid-April you will find fewer accommodations / restaurants / ferries, and the weather can be cool especially in the evening.
There are also fewer buses, which means that without a car it could be difficult to get around the island.

Also be careful when returning to Athens by ferry the day before taking your flight to the US.
In the event of a strike, breakdown or ferry cancellation due to rough seas you could still be stuck on the island while your plane takes off

In a way it's very good that tourism marketing, YouTubers, social media influencers, focus on 3 or 4 islands. Since I'm sure it's not with my few advices that I'm going to change anything, so much the better for the other islands!

We went in April a few years back. Too cold to even think about the beaches other than walking or looking at them. We rented a car and followed Ricks suggested itinerary in his book. Great experience

In our experience, Delphi was crowded and not a must do. For us, Meteora, Sifnos and Athens were the highlights.