I've been an Etsy seller for a couple of years and I didn't need to register my business on that platform. Do I need to do that here or can I just slap on a name to my clothing items and sell'em, like etsy-style?
Yasmin here with Shopify Support!
We don't require you to register a business name to use our platform, so it really depends on the laws in your state or province. However we might ask for a business license if you're using our payment gateway, Shopify Payments.
I recommend getting in touch with an accountant to help you with this. Usually government sites will also provide information on business requirements along with the forms needed to meet them.
Hope this helps!
Like Yasmin M. noted shopify does not have any such requirement.
Business wise you want to start this process earlier than later to secure your trademarks. The process is pretty simple and can remove the insane risk of someone else registering your trademark then suing you* for using it!
*prior use in commerce may defend against this, but always talk to a trademark attorney they make you money in the long run.