Create unique ID based URL for packages for direct link

Right now we have option to redirect client from our LP or packages to register page. I want to have option to also have direct links to each package so while registration user doesn't need to select again (it also prevents confusion in user, like which package he was going for?). I don't want him to turn back and lose interest. So I want my LP has 3 packages, but instead of redirecting to Register page, I want it to go directly connected to each package (create cookie and then show up Register or Login page), further during registration the package he selected on LP gets binded with his cart to proceed checkout. Maybe also auto create an account when someone pays via Stripe then redirects to the app?