If you’re based in New York and you're collecting sales tax (or need to), you must apply for a Sales Tax Certificate (sometimes known as a vendors license in other states). You can apply for this under any legal structure: sole proprietorship, partnership, or corporation. Here's the link to register online for NY: https://www.businessexpress.ny.gov/app/answers/cms/a_id/2058/
New York is a destination-based sales tax state which means that the tax rate is dependent on where the customer is located. If you're selling online, that means there may be a different rate for every customer based on their location in the state. The best way to handle this situation is to sell through an ecommerce platform that does these calculations for you. We recommend Shopify with a sales tax plugin like TaxJar — it's super user friendly and will do the sales tax collection for you!
If you'd like more info on New York sales tax in general, we recommend this guide: https://www.taxjar.com/states/new-york-sales-tax-online/
And if you’d like to chat with one of our tax advisors about your situation, feel free to reach out to firstname.lastname@example.org to schedule a consultation.