Im not sure what you are asking.

If you subscribe to Amazon Prime on a buying account then this will not give you a Prime badge. It enables you to get free next day delivery when buying those items where a Prime badge is showing.

If you want a Prime badge on the items you are selling then you either have to sell through FBA (send goods to Amazon to dispatch for you) or SFP (you dispatch yourself using a Tracked Next Day service and buy the postage via Buy Shipping). You have to ask to join SFP and go through an enrolment process and a trial period where you have to prove you can fulfil the next day delivery promise.

You can be both a Prime Subscriber (buying account) and a FBA/SFP (selling account) using the same account - but most people tend to keep their buying/selling accounts separate.