Based on the presentations done by the Outreach and Engagement SC with the Nextgen students at the ICANN56 and ICANN57 meetings is this Introduction to ICANN At-Large presentation.
This can be used by any ALS to help explain What is At-Large, Key Activities done by At-Large, How to engage in At-Large.
Here's the link to the Google presentation
https://docs.google.com/presentation/d/13jwtJaIyYlz2_mcuY_Ix4Q4z7KAi36TpB6M7_X-2Sj8/edit?usp=sharing