Unique twist on shopping cart - total noob, could use some guidance!
I'm a designer with light programming skills (a lil php/js). I want to make a shopping cart that does the following (site is members only):

User A (Bob) sees a product he think would enjoy with User B (Sarah). Bob sends Sarah an invite to the product. If she accepts, either Bob or Sarah can purchase it, or they can split it. If she rejects, neither of them can buy it. So all products can only be purchased if two members purchase them together, based on this invite system.

I've been looking at opensource solutions (Joomla+JomSocial+VirtueMart as well as other shopping carts) and it seems I hit a wall. I'm willing to man up and try to develop it myself but I don't know where to start (I don't think W3schools counts as a place to start). Any suggestions? What functions am I looking to learn, which coding language would you recommend, are there open source platforms I should be looking at?

Thanks for your understanding of the word "noob" and thanks for your time for answering.
Unique twist on shopping cart - total noob, could use some guidance!
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I'm a designer with light programming skills (a lil php/js). I want to make a shopping cart that does the following (site is members only):

User A (Bob) sees a product he think would enjoy with User B (Sarah). Bob sends Sarah an invite to the product. If she accepts, either Bob or Sarah can purchase it, or they can split it. If she rejects, neither of them can buy it. So all products can only be purchased if two members purchase them together, based on this invite system.

I've been looking at opensource solutions (Joomla+JomSocial+VirtueMart as well as other shopping carts) and it seems I hit a wall. I'm willing to man up and try to develop it myself but I don't know where to start (I don't think W3schools counts as a place to start). Any suggestions? What functions am I looking to learn, which coding language would you recommend, are there open source platforms I should be looking at?

Thanks for your understanding of the word "noob" and thanks for your time for answering.