Popup Questioner /?

hi there guys ,
I'm currently building a e-commerce website with the Django framework and I really want the users or people whom will eventually visit the website to make an account {register} with my website as customers , and I want to suggest them to create an account through a modal , but I don't want the modal to be very intrusive or even pop up every time the user visits the site ,

I'm thinking that the modal or even a small notification bar should show up only after the user has visited my site for a number of times and for a set amount of time ,

*is there a way to track the number of times a person visits my website and how much time they spend on it .
*

also I am open to suggestions on
*how I should convey the message of "please consider creating an account with us" to the user , should it be a modal or a notification banner or something else entirely *

at the end the website is an ecommerce platform for kitchen-ware
and is in very early stages any and all suggestions are welcome

thank you !.