Using cart and checkout in preview mode

I am creating ecomm site with ( 3 ) products ; each has ( 2 ) variants.
I have not yet enabled payment or checkout.
In preview mode the “ADD-TO-CART” doesn’t add products.
In preview mode the cart shows ( 3 ) items in cart although none have been added.
In cart ; “REMOVE” command doesnt work.

Will this all be resolved when I initiate payment and check-out or should this already be working in preview mode?

Here is my site Read-Only:
(how to share your site Read-Only link)