Hi,
Good day to you.
I am Senthilguru , LMSACE Technical Head & Moodle Developer have 8+ year experience in Moodle theme design & integration , Moodle plugin development ,Moodle course creation , Moodle installation & administration.
Here my comments about the integration task you are looking for
#1 I hope you are keeping the Moodle LMS in subfolder where you have hosted the shopify portal.
#2 We can integrate the users between both systems , so users will be created in Moodle automatically when you add users or register users in shopify... for this we will use the Moodle API and shopify hooks (Hope it should have some event triggers for the add user process)
#3 Also we can integrate the login process too , so when user log-in shopify they can their LMS portal private space. Will implement single sign on concept.
#4 Also we will implement the auto enrollment in Moodle course when user purchase the course in shopify (Hope it should have some event trigger)
I would like to have a discussion with you , please respond & let us know if you have any questions.
Have a great day.
Thanks,
Senthilguru.E