First things first-- how do you get into the country? It's super easy. Technically you have to be with one of the 12 qualified reasons to go to Cuba (journalism, charity, education, etc), but nobody on the Cuba side or the US side REALLY checks. When you buy your ticket off Jetblue ($100 each way!), they ask you to sign affidavit that you're not going for only tourism reasons. When you check in, they also sell you a $50 Cuba Visa, including health insurance.
Cuba is real deal communist, as in your US credit card or debit card will not work ANYWHERE. If you have a Chinese unionpay, you will get the best exchange out of anywhere if you just take money out from the ATM's. So make sure you bring enough cash. I would budget in about 10-15 CUC per meal including drinks, and 20-30 CUC a day for a nice casa (check if breakfast is included-- it should be 3-5 CUC if not), and maybe about 20-30 a day for souvenirs and transportation. Better to book your casas in advance on Airbnb, Casa Particular, etc.
Do not change money at the airports, as they will give you a bad exchange rate (only around 85 CUC per 100 usd) . Better at the bank but there will be a long line.
People always hear stories about getting scammed in Cuba, so it's good to speak Spanish or traveling with someone who does. Book your casas first (don't stay in a hotel-- they are always overpriced and very run down) and usually your hosts will help you if you need to book anything or least tell a reasonable price of things.
OR to know the costs of things-- bicycle taxis around Havana (e.g. From old town to hotel nacional) is only about 3 CUC's both ways. The old school taxis are much more expensive around 10-20 CUC. A taxi from Havana to Trinidad is about 150 CUC. NEVER buy Cuban cigars off the street. In havana you can get them at the partagas factory or in the shop above Floridita. Leather shoes are about 15 CUC. Leather baseballs and cigar cases are 3 to 6.
Each american citizen can bring about 30 cigars or $300 worth of cigars back into the US.
Start at the capitol building, which is currently under construction. Keep walking towards the Revolution Museum, which still has bullet holes in it from the war. Spend the morning in that area and check out the Granma memorial as well.
Circle back to Old Town and have lunch at one of the numerous set meal restaurants in the alley called Callejon del Chorro by the Cathedral. Esto no es un Cafe is TripAdvisor ranked, but the lobster is just as good at any other of the small cafes in the alley, and it won't be as pricey.
Watch the sunset at Hotel Ambos, their pina colados come in real pineapples, and their Cuba libres are not bad either. To finish off the night, stop by Floridita for their delicious daquiris and incredible live music. Both are favorite of Ernest Hemmingway.
Another option is to walk along the Malecon until you to the Hotel Nacional, where you can even see the tunnels from the Cuban Missile Crisis.
Spend at least two days there! This was actually my favorite city.
Wake up early, and after eating a hearty breakfast at your casa particular, ask if they can pack a lunch for you (there's not really a place for you to buy food at the beach). Stroll down Gutierrez and rent a bike for 6 CUC. Follow the signs for the 12 km ride to Playa Ancon. On the way back you'll get a number of offers from the returning taxis for a ride. They'll even take your bike. If your squeezed for time, a taxi one way is 10 CUC.
The guard at the large all-inclusive brisas resort, the cubunacan one, will let you let your park your bike for 2 cuc each. That may be pricey but it also means you can sit on the private beach and not pay for chairs either.
In the afternoon, take a stroll around the central plaza, and find the little street that filled with the embroidered linens Trinidad is so well known for. The bracelets made from vintage forks and knives are also beautiful. Leather shoes are cheaper in Santa Clara. But get some beautiful (and incredibly cheap) pottery from ARTISTA DEUSTUA!
The second day in Trinidad explore the waterfalls! Be prepared, it's 4-5 hours each way, but the waterfall is absolutely divine if you can handle that on horseback. You can book through your casa or with this number. Same deal, remember to pack lunch.
Our favorite part of Santa Clara was actually our casa. The house is all vintage that the host buys off radio shows! He's a photographer and his gf has spent time in the US so their English is perfect. The casa was also right next to the Central Plaza as well, where we got to see schoolchildren doing morning exercises, a line to get on a bus to go to the edge of town, and buy fresh flowers.
The must do's in Santa Clara are the Tren Blindado, a fascinating memorial park dedicated the Battle of Santa Clara by a Cuban Artist, and obviously the very well-done Che Guevara Monument. Get to both early, as it gets hot during the day.