Policies, tech, and build order really depend on the situation like the land around you, your civ, how close your neighbors are, your neighbors civs, etc. As a very rough guide to get you started (customize it how you want as you get more experience):
Social Policies:
For science and domination
Tradition Opener>Legalism>Landed Elite>Monarchy>Rest of tradition
After tradition you tend to have 2-3 policies before you get to the renaissance and you can put them in whatever you want. For science I like to go down the left side of patronage. For domination the left of of honor.
At the renaissance for both science and domination start filling out rationalism until you get your ideology. Then pick from either rationalism or ideology depending on what you think will help you the most.
Tech:
For Science:
Pottery>techs needed for luxuries>Writing>Calendar(if you don't already have it)>Philosophy. After that its a bunch of beelines to the key tech you need. Usually it goes Education>Currency>Banking>Scientific Theory>Plastics>Satellites>Rest of techs needed for spacehip parts.
For domination:
Basically the science tech tree until you decided you want to go kill stuff. Then you beeline for the appropriate military tech, make your uber units and go killing. Key military techs include Construction, Machinery, Dynamite, Flight, Rocketry, and Nuclear Fusion
Build Order:
For Science and Domination
Capital
Usually a scout or two>Granary>Shrine>SettlerX2>Library>Oracle>National College
Satellite Cities
Library>Granary>Shrine>Caravans/Cargo ships
Steal workers from the AI. If you cant steal then you need to hard build them or just buy them with gold. A good number of workers is 1 per city. Buy an additional settler so you have 3 settlers (2 hard build 1 bought). Buy libraries with gold if you can, preferably in satellite cities with little early production. Somewhere in there add 4 archers and a spearman so you can defend yourself from barbarians and any other aggressive civs
After that for science focus on Science Buildings>Growth Buildings>Happiness as needed>Gold>Culture>Military.
For domination use the same focus as science until you want to kill stuff, then focus on Military>Happiness>Gold>Science>Growth>Culture.