Need help with Itinerary for 19-20 days Barcelona / Greece/ Greek isles June 2020

@lmurphyfoster - To better plan your Euro trip, I advised you to pick up a copy of the new 2020 edition of Rick Steves' Guide Book for Barcelona and the Greek Isles. You may visit a Barnes and Nobles store and read it there if you don't plan on buying it to get valuable info on airbnbs, side trips, and a whole lot more regarding your destinations. That would be a good guiding tool to get you started then we can fine tune an itinerary if you choose to present it to us.

What happened to Germany/Netherlands?

You have any thoughts on what you want to see; how long you would like to be at each place; "Greek Isles" covers a lot of territory.

You want 2 weeks on an island soaking up sun and just a quick visit in Athens and Barcelona, or intensive city visits and a couple days of beach time?

Your question is so broad, trying to answer it is like trying to grab a handful of fog.

I was in Greece and Italy for about 9 days each this past summer, so I guess I may have something in common with what you are looking for.

A few things to keep in mind before presenting my humble opinion:
1) Barcelona is rather isolated from other "must-see" cities. In particular, one could do many awesome day trips from, say, Madrid or Seville / Malaga / Granada, but not necessarily from Barcelona. (sorry, none of the day trip from Barcelona excites me as "must-see", but it's just me)

2) Amount of travel time between the Greek Cyclades islands is way more than some people think. Ferry's (lack of) punctualness is well known, while the inter-island flights need to change plane in Athens, a major major hassle. I felt like a whole day was lost whenever we hop from island to island. So don't expect to do much during the island hopping travel day.

3) IMHO 3 days are enough for Barcelona (I could argue for 7 days or a month to 10 years, but for starter, 3 days are good). Therefore, I personally wouldn't bother visiting Barcelona just for 3-4 days then spend the rest of 2-3 weeks in Greece, unless I am visiting a family or having business trip there. Just focus on Greece instead.

Having said that, this was our itinerary this past August as an example. Replace the Italy days with Spain days as you see fit.

Day 1: Maranello Italy
Day 2: Pisa Italy
Day 3: Athens Greece
Day 4 - 7: Santorini Greece
Day 8- 11: Crete (Chania) Greece
Day 12: Milan Italy
Day 13-14: Lake Garda Italy . (no debate here... we are saving Lake Como for the Switzerland trip)
Day 15: Verona Italy
Day 16-19: Venice Italy (it didn't feel long at all)

In retrospect,
i) an extra day in Athen would be awesome as the Acropolis need way more time than I envisioned (3 hrs were too rushed, for starter)
ii) Our family isn't crazy about Mykonos, so we skipped it. Many people think it is a must see. Perhaps 2-3 days would be nice.

iii) 4 nights in Santorini still felt way too short.

iv) Crete could easily take 2 weeks as many people alleged ... no kidding ... we only visited the west (Chania) side of the island, saving the east side for another trip (which IMHO, a week is needed)
v) Naxos and Ios are on our radar next trip
vi) it's just not wise to hop more than 3 islands in Greece per trip, IMHO
vii) Olympia / Meteroa / Delphi are way too hot to visit in the summer, we are saving this for next trip instead

If you are active and don't need to bother with kids ... your schedule could be way more fast paced. Hope this helps.

While I adore both Barcelona and Girona, I agree that I don't think a quick visit to Barcelona as part of a 19- to 20-day trip, the rest of which is to be spent in Greece, is a great idea. If Barcelona is you first stop, the first day may be heavily compromised by sleep-deprivation and jetlag. It's a tough city to rush through, because a lot of the most popular sights require pre-purchased, timed, tickets if you want to avoid ticket lines that can he over an hour long. It's difficult to know how far apart to set up those entry times: How much time will you want to spend at each sight? Will you have to wait in line before entry (because of crowding) even though you already have a ticket? How long will it take you to get from Sight A to Sight B? How long will you need for lunch?

As already mentioned, traveling around Greece is much slower than many folks imagine. There are no express trains; in fact there are very few trains, period. So you're talking buses, ferries, or dealing with airports.