How to contact Coca-Cola, Mengniu and other big companies to make outdoor signs for shops?

Hehe, did you just advertise? Save your energy. People are related by blood. Can you put your feet in? Unless you quote a very low price (more rebates) to the local dealers or salesmen, you will not only lose money, but also lose money. If you advertise with brands for a long time, you will be dragged down and have no money.