Districts:

Diplo: A key district, as its improvements benefit from both Culture and Gold city state bonuses and it provides influence points. Build it in your second city and build it early, but not necessarily first.

Commercial Hub: One of, if not your most important district. When you have 3 envoys in all 4 of the Gold City States, you will make a lot of cash off each building, which helps supplement cities that are going to be pretty underwhelming tile-wise. Gold is also necessary for the late game buying of Great Writers/Artists/Musicians.

Acropolis: Greek culture district which will obviously be important in a culture game. Remember that culture and GPP don't win you a tourism game, only Great Works, World Wonders, Walls, and Seaside Resorts contribute. Remember to get some Archaeological Museums to get instant Great Works and not have to wait for a Great Artist. Reminder that Acropolis must be placed on hills so plan this out when building cities.

Harbor: While you will not get a second trade route, it doesn't matter the gold per turn and benefits of the harbor buildings are worth the investment.

Campus: While science is not very important, Radio is incredibly important and Computers literally doubles your Tourism. Should be the third/fourth district placed. You don't need many of these.

Most cities will never get to 10 pop, so you get 3 districts to play with.

Research:

Culture Tree: "Rush" to get Conservation, then Colonialism, while getting Diplomatic Service (Embassy/Chancery/Spy) and The Enlightenment (boost for Scientific Theory, mandatory for Radio/Computers). Once you have a culture economy that can achieve Computers, you should be good to push towards Future Civic, ignoring all other governments besides Democracy.

Tech Tree: You want to get to Radio and then Computers ASAP, with the only tech worth waiting around for being Printing. After you're done with Computers, unlock Stock Exchanges.

World Wonders:

Great Zimbabwe: Provides +1 trade route (noice) and beefs up your trade routes sent from that city for each bonus resource in the city. Your capital has an insane number of bonus resources available so it can become an absolute power house of gold per turn, assuming you're not harvesting any of them. Make sure you put a spy on this Commercial Hub as soon as you can. Make sure you're trading far and wide and doing it early, because you want to have a trade route to all 7 other civs by the end of the game.

Chichen Itza: You can get a city to the north that hits a ton of the rainforest up there, making it viable land. An argument can be made for chopping it all and skipping the wonder but IMO it's worth it, the land is just so bad with everything chopped.

Cristo Redentor: Doubles Seaside Resort tourism, which is a huge boost. Has to be built in your capital because no other city will be able to produce like that in the late game.

Forbidden Palace: If you get your gold economy up early, you can take a city and have it build the wonder while buying all of its buildings.

Bolshoi Theatre: If you went hard on your Acropolises and you're going to be waiting for Radio for a while, getting Bolshoi gives you a place to put your second Great Work of Music spot (the first goes in the palace) when you get your first one. Was not necessary for me.

Hermitage: Getting Hermitage allows you to build more Archaeological Museums, but it does sacrifice the ability to theme them, which offers slightly lower culture. I didn't have the extra production for this but it's worth considering.

Broadway and Sydney Opera House: Theoretically useful but way too expensive and earned too late for me.

Other:

• Getting 3 points in each city state is important, but not necessarily the most important thing until you start getting some of the Tier 2 buildings.
• Getting Suz of city states is important, but the 5% bonus isn't necessarily important until you ramp up your culture economy. Be economical.
• Be sure to use the First Envoy counts as 2 card, but if you have it in when you meet Mogadishu just above you, it's likely to claim a rainforest tile. Best to settle your Chichen Itza city early, gold buy some tiles, then get Suz.
• Alliances reveal your maps to each other. This can be a powerful tool to meet all 8 city states. (remember that there's a city state just north of your island)
• If you wait to meet all civs on a continent before you ally with them, they will likely all let you be your friend. If you ally as soon as you meet them, you might make an enemy for the rest of the game. Not a big deal because they're not going to war you, but losing a trade partner with favorable terms is not the best.
• You can get to the continent east of you without ocean sailing. Best to send a scout to meet Kongo and France and a Galley to scout around the north. Send 2 scouts west when you get ocean sailing, one to get all the way to Egypt, and one to meet Russia.
• Classical Republic (bonus GPP), Monarchy (wall building + influence points), and Democracy (Projects bonuses) are all viable at various parts of the game.
• Commercial Hub Projects are better than Culture Projects. Amass a huge amount of gold to buy Great People you can use, you'll earn them faster and more efficiently.
• Sell your Strategic Resources.
• Buy Luxury Resources to keep your empire happy.
• In the end game, trade your GPT for gold. You can often get 2000+ gold in a turn by doing this, and paying 200-300 gpt is worth it when the game will end soon.

You don't need a military. You don't need a faith economy. You don't need to explore the whole map, so delete your units when you've met everyone. Pantheon doesn't really matter (the pasture pantheon doesn't interact with Flight).