My recommendation if you are starting a fashion brand and you don’t have a lot of products (that’s usually the case at first) is to go with WordPress + Woocommerce.
Why ? Because WordPress and Woocommerce are free and open-source softwares. All you will have to pay are the domain name, the hosting plan, a few plugins. If you don’t know anything, you might need to hire a developper at first and to develop some knowledge on how to maintain and add your products but in the long run, it’s the solution that will cost you the least. Therefore, you can afford to make mistakes and change things if you need to. It’s beginner-friendly and you can use drag and drop templates like elementor to make your life easier.
On top of that, it’s a great platform for SEO, ie, what makes your website rank and seen on the first pages of search engines.