Try this :
First turns, put all on production for 4 wariors, and use them for quick exploration and getting huts and barbs.
Once the 4th warior is made, put all on food (unless you are using romans, chinese or Egypt with hanging gardens, in which case you skip this) and grow to 3 population.
Once you have 3 pop, hammer a settler and put it in a nice spot, depending on who you have met, how far they are, and how good you are at rushing.
I prefer making my first city (not the capital) a city that has at least 3 forests and 2 food sources or more so i can make a good deal of archers (chokepoint-securers) and buy bronze-working from the computer civs who offer it for 20-85 gold (i pay 35 max).
Once you have your second city (Capital + settler you made), you'll most likely get your 100 gold settler to make a nice science city having 3 or more sea (or desert if you use egypt).
you should then grow your capital, and have at least one archer in each city (for now, you want to use your turns in a way that gives you most benefit for later, so grab that food and grow!).
Should you not know what to research (new players need to learn) ;
--if an enemy is close-by and doesn't seem to have a lot of defenses, go for iron working.
--if they are further away, and chokepoints are secured so they won't be able to bother you, go for pottery - masonry (free wall if your first) - irrigation (+1 pop if first) - construction (if you have a city with a lot of hills) and then go for alphabet and so on...
you are not going to build libraries early on, unless theres a city that's really worth it (island with 5 or more sea and at least 2 fish for growing)
From there on, just go for Code of Laws and get in a republic so settlers cost only 1 pop, and spam away with settlers!
-Offline means your turns can last as long as you want, so city management can't be a problem
You will be able to win from there on, trust me, it's only King, so they won't be that good at science and making armies
One golden rule : Never Ever eeeeeeveeeeeeeeer have your cities on both food, hammers and science or gold production at the same time in early game, unless you need 2 more gold for the free settler, but else, never do it!
Its a mistake the ai makes, not players who want to win