OK, looked at the save and I have some initial diagnostics/state assessments, and then some thoughts and recommendations. to be brutally frank, you've underplayed this in a lot of ways, but that's where learning comes from. And all is not lost -- this is Prince, after all, where AI victories come very late (often well after turn 400), so there's ample time to turn this into a romp.
Babs, G&K, Prince, Continents, Standard speed, turn 284. BPT is now 420 (due to shifting to work specialists), but culture is 50 cpt, and your finances are pitiful (32 gold and 0 gpt.
You've settled 10 cities, but they are all undersized -- capital is 11 (34 turns to next citizen), Akkad is 10, and the rest range from 4 to 9, and growing slowly or stagnated. Babylon has two academies planted on flood plains tiles, but other flood plains and other farmable tiles are unimproved. You also have very poor production in your capital (17 hammers), with unimproved forests that could either have lumbermills or be chopped for production and then farmed.
In fact, you only have 4 workers in your entire empire, and 3 of them are asleep. You have needed more workers for ages, and you need to work the workers you have. Tile improvements (other than roads) cost no maintenance, and your citizens should not be working unimproved tiles--that is borderline criminal neglect of your empire's subjects.
On military, you have 16 crossbows, 1 upgradeable composite bow, a musketman, 2 longswords, a pike and two spearmen -- on Prince. Why? Your deal history shows no peace treaties and you aren't at war with anyone, so why have you invested so much in military. That said, you haven't put any boats in the water, so you haven't fully explored the coastline of your own continent and know nothing about the 4 civs on the other continent. You've only met 7 CSs, so half or more of the CSs out there are strangers to you. You've had Astronomy for a while; spit out a couple of caravels and see the world.
Social policies are also a bit confusing. You took Liberty, which makes sense for a wide empire, and then a couple of points in Commerce, which is OK but not great (some points in Patronage would have helped you ally some maritime CSs for food and cultural CSs for culture), and then opened Rationalism (good), but then went down the right side of Rationalism (Humanism and Sovereignty), rather than the left side (the side with the ... um ... actual science contribution). For a science game, left side of Rationalism! (Frankly for a diplomatic or domination game, left side of Rationalism also.) And, because your culture rate is low, it's 29 turns to your next policy, so it will be a long slog to get your policy choices on the right track.
On wonders, you've been reasonably restrained, but Colossus in a city with only one sea resource tile was a questionable choice -- probably would have been a better use for those hammers. Same goes for Natinal Treasury in your capital -- you have more important things to build there, like a granary, aqueduct and garden In fact, none of your cities have granaries or aqueducts, but they all have walls. Given how peaceful things are, walls should not have had priority over granaries and aqueducts.
By working most of your specialists, you are now up to 420 beakers per turn, which is light for the late 200s. It's undoubtedly better than where you were not long ago, but not as good as it would be with the left side Rationalism policies. Still, your cities can't grow, so you are likely to stagnate at this level as your enemies pick up steam.
And your competition is racing ahead. On this continent, Germany now has 17-18 cities, and has taken over the tech lead. Hmmm, maybe your army will come in for some use.
I think you need to get your workers farming up a storm (spit out a few more to help) and focus non city growth (granaries ASAP, and Fertilizer may be your best next tech - 5 turns).
I think I'm going to play your save forward a bit and then report back (with spoiler tags).
