So many questions. Let me take a stab at a few.
A common build order in your capital will be scout (scouting is critical, for a host of reasons), monument, shrine (if you have G&K and want a pantheon). From that point, your choices will vary. Many will start on a worker at that point, while others will aim to buy a worker (with ancient ruins gold, CS meeting gold, CS bullying gold and/or gpt-for-gold loans from the AI) or steal a worker from a CS, and instead build a granary or a second scout (particularly on a larger map), another warrior or an archer. Building a settler is usually delayed until your capital is at 4 or 5 population; your capital stagnates while building a settler, so you want enough citizens working tiles to make the settler production/stagnatin time as short as possible.
For second city locations, preferences vary widely, but you will generally want to find a location that has at least one new type of luxury resource (your founded city costs 3 happiness for the city and 1 happiness for each citizen, so a new luxury that provides 4 happiness essentially "pays" for the happiness hit of founding an additional city), good food supplies (at least one "extra" food tile -- food in exceess of 2 food per tile), and at least decent production capacity (a couple of hills that can be mined or forests (for chopping or for lumbermills)), and preferably on a river (fror the gold income) -- not every city can have all of these features, but they scratch the main itches of a new city -- happiness, growth, production and income.
When you found a city, keep defense in mind. Don't settle too far from your capital (stay within, say, 3-4 turns of warrior/archer movement), don't settle in the face of an AI civ (even if the location is sweet--dealing with a DOW can rob that new city of much of its joy) and try to settle behind rivers and on hills (if I only have a choice between behind a river or on a hill on the other side of the river, I'll usually take the hill).
I would also advise that you watch some Let's Play videos (check the Stories and Let's Plays section of these forums or YouTube) and browse these forums -- you'll learn a lot, and pretty quickly.