Hello Brian,
The template files can be found within the /learnpress plugin directory/templates/… You can edit these files in an upgrade safe way through overrides. Simply copy it into a directory within your theme named /learnpress, keeping the same file structure, but removing the /templates/ subdirectory. In your case, you should override file single-course.php, call your sidebar in wherever you want.
Thanks for your concern.
LearnPress team.