4
Announcing .NET 8 Preview 5 - .NET Blog
(devblogs.microsoft.com)
Getting started
Useful resources
IDEs and code editors
Tools
Rules
Related communities
Wikipedia pages
And here I am learning C# 10 and .NET 6.
The changes between version are very incremental and mostly just adding new things.
You don't even really need to learn all the features for each version.