Here are some official Microsoft websites that you really should bookmark when studying for the AZ-204 exam:
Learning paths on MS Learn:
https://docs.microsoft.com/en-us/learn/certifications/exams/az-204#two-ways-to-prepare
Azure Code Samples:
https://azure.microsoft.com/en-us/resources/samples/?sort=0
Official Azure Documentation:
https://docs.microsoft.com/en-us/azure/
Official Microsoft Azure YouTube Channel
https://www.youtube.com/user/windowsazure
Official Microsoft Developer YouTube Channel
https://www.youtube.com/channel/UCsMica-v34Irf9KVTh6xx-g
Azure REST API Browser
https://docs.microsoft.com/en-us/rest/api/?view=Azure
Microsoft Labs and Workshops – Practice is the key to success
Azure Citadel – Labs and Workshops
Microsoft Cloud Workshop – More labs and workshops
https://microsoftcloudworkshop.com/
Github AZ-204 from Microsoft Training
https://microsoftlearning.github.io/AZ-204-DevelopingSolutionsforMicrosoftAzure/