Your products are photographed, the descriptions are written, and the website is nearly ready. That leaves the question most people put off until the last minute: how do you accept payments in an online shop and actually get paid?
Taking payments looks like a single technical step. In practice, it is several separate pieces: registered business activity, somewhere to sell online, a payment gateway, and shop terms with a privacy policy.
Until every piece is in place, you cannot complete a sale. Below is what you need at the start, and in what order to set it up.