Checkout is not available whilst your cart is empty – Woocommerce
This is an issue for many, and there are a lot of forums on how to fix this issue, so I’ll link to some, but my issue was actually quite simple.
I installed Woocommerce on this website >>Store Link Here<< but somehow all of my Woocommerce pages were set to “Draft”. I don’t know how it happened, but it did and I would advise doing the following before doing anything else:
Go to Pages and make sure Cart, Checkout and My Account are set to “Published.” If not, select “Edit” or “Quick Edit” and select “Published” > Save.
If your pages are published, make sure they have the correct Woocommerce shortcodes that trigger actions for each specific page.
The shortcode for all these pages are as follows and literally just copy and paste into the visual text editor and Save.
Your cart is currently empty.
This may not be your problem, but as with anything, always start with the simplest solutions so you don’t expound the problem and pull all your hair out in the process.
If this is not your issue, here is a link to an article that runs down several possible fixes: