How do I know the size of my world, and its population
I've been doing this map, helped by one of the great tutorials found here. I'm writing a story that takes place in this world I'm mapping, and now that my map is almost finished, I encounter some problems.
The first one is that I don't really know the size of my world. I mean, I Ŧfeelŧ its size, enough to draw borders, places cities, and those sort of things, but I could not make any scale bar. And as I'm writing a story about it, this is the kind of things I should know, in order to be more coherent to my readers. Do you have any ideas how to proceed? I know that some characters travel by boat on a river between two points in two or three weeks, but I don't know the speed of a ship... Do some of you know that kind of stuff? That, or the number of kilometers one man can travel in a day in foot/ on horse? That could help me define the distances, but if there's is any other ways...
My second problem is the population of my world. I have absolutely NO idea how many people live in a country/ big city/ town/ village. My story takes place in a middle ages - renaissance - pre industrial world. How do I know what is a credible population for my world? And, by extension, how big an army must be? In other words, is there a guide to creating a fantasy world?
Thanks for your support!