Ok, figured it out. The mod developer has seem to have cut out the land buying version that is in the original "mount & blade warband" and replaced it with purchasable enterprises (brewery, metal smith, tannery, winery etc.) that can be bought at every city.

At first I couldnt see where my enterprise is listed, but its listed in the budget financial screen. (same screen that shows you how much troops get paid weekly) You get money every week which is great revenue.