@ITLJames,
To connect your "Take This Course" Button with an external link, you have to enable a setting, Go to wp_admin -> LMS -> settings -> course pricing settings -> enable course external link refer:
http://prntscr.com/gytbpk
After enabling course external link setting, when you edit course there is a option of pricing in it. In that setting you'll find an option to "connect course button to an external link". Paste your custom page url in it refer :
http://prntscr.com/gytcgf
When user click on "take this course" button then that button will redirect the user to your custom page.