I think you can take a look on the training that Xamarin University provides or wait for that Microsoft release the content on "Microsoft Learn" platform.
On the other hand, the Xamarin documentation is very self explained and the Planet Xamarin blog contain a lot of resources in specific topics written by the community.
Links: docs.microsoft.com/en-us/learn university.xamarin.com docs.microsoft.com/en-us/xamarin planetxamarin.com