After importing the demo data you gotta select the LearnPress Pages from the LearnPress settings.
Note: LearnPress plugin creates few pages when it’s installed. If you import this theme demo you will have those pages as well.
Now it’s time to select those pages from the LearnPress settings.
Navigate to the LearnPress > Settings > Pages. Here you will see like the screenshot below. Select the Profile page, from the profile dropdown.
Select Pages tab to set Become a teacher page, as the screenshot below.
Select Payments tab to set the checkout page, as the screenshot below.