How to track each individual click through data in an e-commerce website through google analytics.

How to track each individual click through data in an e-commerce website
through google analytics.

I want to track each individual user click through data on an e-commerce
website using google analytics.
Suppose user A arrives on the website then what he clicks next, what time
he spends on each page, whether he opens a related product or opens up a
new unrelated product, or add a product to his wishlist, or he put a
comment on a product, or he shares it on social media, or simply buy a
product or search for a product in the search bar. In all, the page flow
of each individual and user session has to be tracked.
I was trying this using custom variables. Is this a correct way of
approaching it. Or there could be some other better techniques. Also
provide me proper references for both.