When working with Elementor to customize the look and feel of LearnDash pages, it is important to note that it is recommended to not directly edit LearnDash associated pages such as Courses, Lessons, Topics, Groups, etc. with Elementor, and rather create a template through Elementor’s Theme Builder (available in Elementor Pro) to create templates for each of these items. Then, you can add the content through the Course/Lesson/Topic page respectively. Depending on the display conditions, the page respectively will be covered by the template layout you have created for that specific post type with Elementor.
Also, to avoid any predefined elements by your theme to appear in the Elementor editor, it is suggested to use either the ‘Elementor Full width’ or ‘Elementor Canvas’ template layout in Elementor settings. This will allow you to get rid of any unwanted elements implemented by your active theme. Please note that this setting is in the Elementor side of things. You can find more information about this in the following article from the official Elementor documentation: https://elementor.com/help/canvas-vs-full-width/
To create the layout for a Course Page, you create a Single Course Template in Elementor. The same applies for Lessons, Topics, etc.
Please see the instructions below:
You can create a “Single Post Template” in Elementor theme builder, and then with the “Display Conditions” assign the template to a Course.
Important to note: If LearnDash Focus Mode is enabled on your website, please note that Elementor templates will not have any effect as Focus Mode has the priority for displaying Lessons/Topics, etc. Currently, Focus Mode layout cannot be edited with Elementor.
In your WordPress Dashboard, please go to the Templates option below Elementor and click on “Theme Builder”.

Then, go to the Single Post tab as follows and click on “Add New”

A modal box will appear. Please make sure that “Single Post” is selected in the dropdown. A name can be input in the “Name” field, however this is optional.

Then click the green Create Template button.
NOTE: Alternatively, instead of creating a Single Post Template, you can create a ‘Single Course Template’ simply by choosing Single Course instead of Single Post. Then follow along with the same steps below.
After the page loads, it will present you with a new modal to pick a Template. If you want to work with a premade template, you can insert it into your post from this window. However, this is not required. If you are going to start building from scratch, you can simply click the close button in the top right corner of the modal:

In this example I’m not using any templates, so after closing the modal, the page will appear “blank”. Here you can start building the layout for your Course Page. Feel free to use the widgets as you prefer. For the most basic usage, you need to use the Post Title and Post Content widgets. The Post Title will display the Course name and the Post Content widget will retrieve the main Course content:

NOTE: If using Single Course Template, you can use ‘Course Content’ widget instead of ‘Post Content’ widget.
Just drag and drop the widgets on the screen. These will display as a gray box in the editor as the content is loaded dynamically when visiting the Course page. But in order for the Course page to “recognize” the layout, a last step is required, that is to set the display conditions to the correct post type.
So, after you have designed your layout according to your needs, please head over to the Display Conditions menu:

A modal will open. Please click the “Add condition” button:

A dropdown will appear with some options. Please make sure that the first option is set to “Include” and on the second drop down, please scroll down to “Courses”.

Once you have set the display conditions according to your needs, please click the green “Save & Close” button at the right corner of the modal.
Please test this by visiting the page of your Course.
NOTE: These instructions can be applied for Single Lesson Page, Single Topic Page, Single Group Page, etc., as needed. It would simply require, after creating the corresponding template, to slightly change the condition to match the LearnDash related page respectively (course/topic/group, etc.), which would be required if creating the template from the Single Post Template. You can alternatively create the template directly as ‘Single Course Template’, ‘Single Lesson Template’, etc., and you will only have the display conditions for that specific type of Template 🙂