In regards to sourcing products, International Trade Shows are the places where contacts are made.
In regards to the distributorship, it does of course depend on the size of the company you are dealing with, but most sole distributorships are sorted out between legal teams mostly.
You are talking about contract law here, so you are talking about yourself paying out a massive amount of money up front, that's just to cover your legal team. Before it gets to that point, you would need to prove to the supplier that you had a network in place that could service the customers and the companies needs.
Unless you have a substantial amount of money, a company profile and an effective distribution network ready to go, they won't even take your phone call.