How to get vat/cst numbers to sell on online shopping portals

Hello, I am from Delhi. I am planning to start online selling on online shopping portals like amazon, snapdeal and flipkart etc from my home. Apart from that I won't sell anything offline or from shop and delivery will be handled by the online portals itself. I registered account on these online portals but everyone is required vat/cst numbers, pan card, bank account etc. I am currently having my personal pan card and saving account details. I am stuck with the vat/cst issue. I am planning to sell laptop bags, women accessories, kitchen accessories and stuff etc. I consulted with one legal adviser and he told me that (Or as I understood him) in terms of getting the vat/cst I will have to register the company first as proprietorship and then the vat/cst etc will be applied then I will have to apply for the company pan number and company current account to start selling with the shopping portals. I am very confused about all these things... can please someone advise me the correct procedure and provide me the correct details about this. Your advise will be really appreciated. Looking for the help from you guys.