Web design and development
Do I need Wordpress, Wix or Squarespace?
You do not. Those make sense if you want to build and edit everything yourself. A site built on a modern framework usually avoids the page-builder subscription and the plugin upkeep, and ties you to no platform that can change its pricing. You still pay for hosting and a domain, as with any website.
Next step
Tell me about the business. Get a fixed quote.
A few lines on what you sell, who buys it and what is not working yet. I reply myself within one business day, and the price comes in writing before any work starts.