Hi,
You indeed do not want to cache anything related to the cart or the checkout since it's unique to the current user.
If you don't have tens of thousands of products or more in your shop, I would recommend to actually exclude HikaShop altogether in the "Exclude components" setting. That should probably be the best.
Besides the products and categories on the frontend, everything needs to be dynamic. And even for the products, if you have prices for different users / user groups, you also want that to be dynamic.
A shopping cart usually has to be excluded from caching.