Thank you for your message, I would be happy to offer you some suggestions for this idea. We actually have a great and very in-depth guide for disabling your cart that you can check out here. It's worth noting that, this customization is for vintage Shopify themes, and doesn't apply to Online Store 2.0 themes. If you are using a third-party theme, you may want to reach out to the developers of your theme to look into the possibility of this request on their end.
Another method would be to simply turn on your storefront password under Online store>Preferences:
However, this method would of course not allow access to your shop until you disable the password, or utilize it to enter the shop. So, if you want customers to be able to still view the shop, simply not be able to add products to the cart, I would suggest my first suggestion.
Please feel free to reach back out here with any questions you may have, we are always happy to help out!
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