How to Sell a Branded Products on Amazon. What's the Listing procedure and selling procedure.?

hello, i am a new seller on amazon and i would like some help from you guys, please. where can i get a manufacturer in the United States? How do i know what products to sell?

I want to ship my products to Amazon as soon as possible, but I have not completed my brand registration, so I cannot create an ASIN with a brand to get the FNSKU code for shipment. The only thing I can do now is to create a non-branded ASIN to get the FNSKU. May I create an empty shell ASIN like now, and after my goods arrive at the Amazon warehouse, I will create a branded ASIN and map these goods to the new ASIN? Or without creating a new branded ASIN, is there a way to change the brand of this non-branded ASIN after my brand registration is completed, and still use this ASIN for sales?