To add a page my website to allow customers to purchase items

I have a catering company, with a webiste built 2 years ago. At the moment, I make small updates to the website on wordpress, changing pictures and text etc but that's pretty much where it ends!

I need a page added that will allow customers to add products to their basket, book a date for delivery and pay for the items. I use square up as our payment system, I'm pretty sure that can link in to my website to process payments.

As it's catering delivery, I am limited to what we can make and deliver each day. I would need to be able to set a limit on product availability, so when a date sells out, customers would no longer be able to select that day. I will also be taking bookings via the normal channels, so I would need a way to update availability throughout the day.

Looking for this to be completed within the next 7 days so I can launch our Christmas range.

Thanks!