Sharepoint Migration & Trainning

I am considering migrating from SharePoint to Azure Blob Storage due to the need for a highly customized solution. The migration must account for granular ownership structures at the file level, requiring that each file (or group of files) be associated with a specific GUID. Market solutions do not seem flexible enough for this requirement.

To achieve this, I plan to use CSOM (Microsoft.Sharepoint.Client) for deep integration. Could anyone recommend reliable training resources or best practices for advanced CSOM usage?

Any insights would be greatly appreciated.