There are many great resources for learning the principles of Clean Architecture, but a the best place to start is with Jason Taylor’s videos:
Check out the Awesome Clean Architecture repo for a community driven up-to-date list of CA resources.
Start with Robert C. Martin (aka ‘Uncle Bob’)’s blog post: The Clean Architecture.
Then, check out this book by Robert C. Martin should be anyone’s starting point for reading further:
Figure: Clean Architecture: A Craftsman's Guide to Software Structure and Design
Also, this resource by Steve Smith is available as an online e-book and contains up-to-date specific examples for ASP.NET Core and Azure:
Figure: Architecting Modern Web Applications with ASP.NET Core and Microsoft Azure