When you install and set up the MemberPress Courses add-on, your courses will use the default slugs in the URLs.
This document will show you steps to change course slugs, and to ensure changes are correctly applied to your website.
Slugs
If you head into Dashboard > MP Courses > Settings > Slugs after installing MemberPress courses, you'll find the settings for the course, lesson, and quiz slugs.
You can add your own name to each option to update them. For example, you could rename lessons to topics, and then update the options.
Following this, it's recommended to flush your permalinks. To do this, head into Dashboard > Settings > Permalinks and save the page without making any changes to the individual options. Also, you might need to clear your website and browser cache.
Once these steps are complete, you can navigate to your course on the site's front end to see the URL change.
String Change
The best option to change the wording of courses and lessons as strings elsewhere on your site is to use Loco Translate. You can update all instances (course, courses, lessons, lessons, quiz, quizzes) to match the slug update you've made across your site.