Many organizations are closed now which may provide some people with time they don't ordinarily have to learn new skills. If you know of any free training resources that may help people learn something new during this time, please share the information here.
Chiming in to mention that Brent Ozar Unlimited is offering their Fundamentals of Index Tuning and Fundamentals of Query Tuning classes for free until April 1st:
https://mailchi.mp/brentozar/free-sql-server-training-during-the-quarantines?e=2a1dd61edc
Both of those courses use How to Think Like the SQL Server Engine as a prerequisite, which is always free, and I can’t recommend it highly enough for people who want to know a little more about what’s going on inside your database: https://www.brentozar.com/training/think-like-sql-server-engine/