in two words, two sided networks usually have a "hard part". in the case of uber, the drivers. in your case, i'd probably "do things that don't scale" like brian chesky did with airbnb, start with a super small location (probably where you live) and drive yourself / your cofounders / friends all the packages until people know the product works.
usually, with cold start products, you have to solve it many times in many locations. you can't do it worldwide day one.