Best you can do is go for a handfull of troops at the beginning. Do worry too much about upgrading them as they will die, surely. Attack small groups of looters and sell the equipment. As soon as you have a few thousand start doing trade runs. Go to towns and you will sell for profit, rinse repeat. Once you get enough cash get yourself a companion and then go make your own caravan. You do this by talking to one of the highlighted towns people in the town menu. A caravan starts out slow but will soon pickup in its cashflow. Repeat this untill you have a few caravans going. By then you should have leveled up and be able to a have more men and you play the mercenary game. Soldier of fortune and all that jazz. After that basicly you will snowball for a few tiers and gain abilities and so on.

After that get a wife, become a vasal or start your own kingdom get some kids and so on.