I think the starting strat (including build and research) depends on the overal strat you want to use.
Since I´m a builder, my overall goal is to get as much land as possible ASAP to found 6 - 10 cities myself. To do so, I always try to build my capital on a plain hill (extra hammer) even if I have to spend up to 3 turns walking there and don´t care much for the surrounding lands.
My build order is worker (warrior when possible to grow the city to size 2 in this time), worker, settler, warrior then axmen or chariot (depends on resources nearby), settler, worker.
The next city is founded ontop or next to horses/bronze and will build an axmen or a chariot (both workers going there to do the work), then worker, settler.
When you build the second city early enough you can bring out at least one axe/charriot before the barbs strart to run into your cultural territory
When doing so, about 1600 BC you can have 2 axes/charriots for defense against barbs, 2 warriors, 4 cities and 4 workers
When you then place the cities (except the second city, which must bring in horses/bronze) always in direction of the AI´s, with 4 cities you should be able to block of some more land to settle later (chop obelisks ASAP).
Research order: go bronze working for chopping, when no bronze near, then animal husbandry to see horses, then everything that lets you improve the surrounding lands
Attached a screenshot taken out of the world-builder (1640 BC) to show you, that even on deity is is possilbe to keep up (almost) with the expansion speed of the AI´s (Vanilla version):
1 AI with 3 cities (white)
2 AI´s with 4 cities (blue and tan?)
3 AI´s with 5 cities (green, orange and light blue)
View attachment 145199
So with our 4 cities, we are doing quite good. Since the AI is dumb, blocking him off like that works fairly good and normally lets you build 6 - 10 cities altogether. When you don´t open borders with your neighbours, you can relax after your blocking cities are founded, research codes of law, lightbulb philosophy, trade that for currency and only then build the backland cities (to avoid beeing broke)