Your site is an e-commerce website, and therefore many pages would not be suitable for caching, as they need to remain “dynamic”, that is, they need to be regenerated by the origin for every visit.
You’d need to figure out exactly what can be cached without interfering on your website functionality. Then you can create rules that prevent these files from being cached. Assuming for example that all the pages on your website that must remain dynamic are either on a folder /cart or /payment, then you could have 3 page rules:
/cart* >>> Cache Level: Bypass
/payment* >>> Cache Level: Bypass
/* >>> Cache Level: Cache Everything
This would avoid that one client’s information (purchases, navigation history etc) is made available to others, which could probably happen if you set “cache everytthing” for all pages on an e-commerce site.