I've installed the theme and started playing with the appearance but I really don't know how to do this. Can you help me? The site is not live yet, that's why I'm not linking it at the moment. I want it to look like the landing page theme http://preview.themeforest.net/item/leadinjection-landing-page-theme/full_screen_preview/14532230 specifically for online course.
Did you try the "One Click Installation"? Have a look at the following video:
Regards, Support Teamleadinjection.io