I recently discovered that Microsoft is offering a free training for their AZ-900 Microsoft Azure Fundamentals Certification.

Find it here:
https://learn.microsoft.com/en-us/training/courses/az-900t00

There are also a lot of free video courses about AZ-900 on Youtube.

https://youtube.com/playlist?list=PLGjZwEtPN7j-Q59JYso3L4_yoCjj2syrM