Time for a long weekend in Cuba -- you can always extend and do much more, but 3 days is the great amount of time to explore Havana. The rest of the country will take much, much longer.
This itinerary is focused on seeing the REAL CUBA and not what fancy tours would take you on. You experience life closely to what the Habaneros (people living in Havana to), with some extra luxury but not much.
Make sure you have your walking shoes on!
*Do your research before you go, LOTS of things about Cuba are different from other places you've been before.
Money -- Bring cash. If you're American, your credit card will not work here. Your bank card won't either. Cash in dollars will get you a poor exchange rate, so if you have some old Euros laying around, now is the time to use them. Change enough in the airport to get to where you need to go (ask your Airbnb owner about pricing for rides so you don't get ripped off -- I did, but that's ok).
Day 1 -- Arrival, find water! Visit grocery stores and small restaurants in general, Art market
It's pretty hard to find non-sparkling water in many of the grocery stores. For me, I didn't find any until my second day, but luckily I had a ton from the airport in Miami that helped me until I was able to get more settled.
People in Havana have learned to live with less -- alcohol is easy to find (make that mojito?) but water is harder to come by. When you find it, buy a lot!
It was really interesting to me to see the products in grocery stores, the lines to wait, and the prices. It's not a great idea to take pictures everywhere you go, because people mind find this offensive, but it IS a good idea to visit the small markets to better understand life for many Cubans in Havana.
You should also find some small shops that sell ham sandwiches, cheese sandwiches, spaghetti, and other similar items. Ice cream shops are all over Havana. You could make a point to visit Coppelia, the ice cream shop preferred by Fidel Castro. When I went to take a look, lines were around the block. I'm lactose intolerant, but I heard it was great!
Still looking to shop? What about some markets?
Best art market! -- this place was breathtaking. The creativity of Cubans doesn't surprise me. There are some little restaurants across the street from this place where you can get some sandwiches and sodas.
Day 2 - walking tour and night life
I'll do anything to save some money, so before my walking tour I decided to walk 30 blocks to where I had to meet my guide. Everywhere you go in Cuba you see people hanging around, but in my three days there I never felt unsafe, even if I didn't know where I was going. As a solo traveler, this is rare!
I headed to Airbnb experiences to check out some walking tours. There are free walking tours that you can find, but it's really important to actually support the Cuban people if you are going to Cuba under the reasoning "support of the Cuban people." I took a great tour with Alberto -- he was bilingual, though the other person on the tour was an English speaker so that's what we did! We met at a local ice cream shop and Alberto showed us most of New Havana. This was the one time on the trip that I ate at a "fancy" restaurant -- best mojito ever, good plantains, squid, and more! Even Alberto explained that some people/companies/etc get access to ingredients that others do not.
Looking for a fancy place to have a daiquiri and maybe smoke a cigar? Check out El Floridita -- famous because Hemingway used to go there all the time. There were some great book stores in this area too. If you can read Spanish, might want to bring some reading materials back on the plane.
After my great walking tour, I had a few hours to kill before going to the Art Factory (La Fabrica de Arte) for some fabulous night life. I went to check out the Capitol Building -- one that will leave you thinking you're in Washington DC. In this zone there are some fancy rooftop bars that you can visit and take in the views, or you could grab a sandwich from a small shop and hang out in the big park where the double decker buses line up.
Day 3 - more walking and sightseeing
In my three days in Cuba, I walked 65,000 steps. That's the kind of vacation I like to take! There is an abundance of taxis, the Cuban equivalent of a tuk tuk (three wheeled vehicle), and even guys on bikes wanting to cart you around.
Need a break? Negotiate a fair price with one of the classic car drivers and have him take you around the city. Remember, everyone in Cuba is trying to make some money and tourism is a big part of that. If you have the extra cash, don't feel like you need to negotiate down to an incredibly low price. Negotiate some, but realize that this job might be that person's livelihood for them and their family!
Important things to see:
1) Hotel Nacional -- very informative tour, beautiful grounds, interesting history, and a great place to sit and take a break from the hot sun!
2) Fusterlandia -- you'll need a car or some transportation to get to this place out of town. This fantasy land will give you LOTS to look at as you try to take in all of the art.
3) The Capitol Building -- beautiful and again, a great place to take a break from the hot Cuba sun.
4) Plaza de la Revolucion -- You've probably seen the large iconic statues/pieces of art conmemorating Che (not actually Cuban) and and Camilo Cienfuegos.
*I thought it was VERY well worth it to buy the pass for the double decker bus. I only bought a day pass, but I think you could spend more time to be able to see the area beaches and other neighborhoods.
The street art alone will take you years to look at. The colors in Havana are SO beautiful, the people are so creative and helpful. You'll want to be back to see more of the country when you have more time.
Don't forget to wake up for sunrise (or sunset!) if you're lucky enough to have an airbnb that has windows facing that way (going back, I would DEFINITELY make this a priority!). It is STUNNING. Plus if you're up early, you can come back to the airbnb for a nap when the sun is at its hottest during the day.