Sensei has four default widgets for you to use on the front-end of your theme. You will find these under Appearance > Widgets.
Category Courses – Outputs a list of courses in a chosen category
Course Categories – Outputs a list of course categories
Course Component – Outputs a list of courses, either new, featured, free, paid, active, or completed courses
Lesson Component – Outputs a list of the latest lessons for the site
Additionally, by installing the free Sensei Course Progress extension on your site you’ll get access to an extra widget:
Course Progress – Displays all the lessons in the current course or module, and lets your learners see, at a glance, which ones they have completed and which they have yet to take.