Do I want a 'pop-up' feature or something else? [closed]

I have nearly finished building my first website in django and I have an 'add to cart' feature of sorts on a product page. The problem is that the 'products' are locations people can visit, and they can add them to their itinerary (the checkout) to create custom itineraries that include solely activities they wish to do.

The building of an itinerary using an 'add to cart' feature, which is just a + icon with a 'add to your trip' tooltip, is proving to be not intrinsically easy to understand for people using the site. So I was thinking of implementing some sort of instructional pop up illustrating the process / feature the first time they enter the page.

What I've struggled to determine is whether a 'pop-up' is the right thing to be building for the website. Since this feature is sometimes disabled on the end-users browser. This is what I would like some advice on. Should I be looking at a pop-up or some other sort of overlay feature to achieve this?

Appreciate any advice.