Well, in my experience, on monarch, u cannot ever make sure expectations, really. A lot depends on terrain. After I have scouted the significant territory around me, I think hard, for a long time, where im gonna put my cities, what resources im gonna get (and ok sometimes i even cheat and look at worldbuilder and see if im getting vital later resource(oil,aluminum,coal,depending), cause if not, then u are gonna waste a lot of time in a pointless struggle...), and this will determine what victories are looking the most promising.
But sometimes, the stupid AI throws this super obnoxious wrench in your plans, by say sending out a settler and setting up camp in exactly the most vital spot for you. This will force you to adjust your plans accordingly. Maybe you can capture the city, maybe you can culture flip it, or maybe you can alter your whole plan accordingly. I find that there is a lot of speculative if this then this sort of planning, and timelines become pretty impossible to adhere to, if you arent the kind of guy who likes to restart every time theres an issue.
If you got a lot of flat grassland and rivers, then you can expect one sort of thing. If you got a lot of coast, u can expect another, if a lot of plains and hills, then another.
Diplomacy becomes your only way to really fill in the gaps, and its super important. At least one other civ is going to outpace you hoplessly. Always. You cant drag them down alone, u gotta make friends, and quickly, and be faithful to them, and use them to drag the powerhouses down.