Take time to learn the very basics from Microsoft Learn and training videos at Microsoft.
Next, figure out a project you want to create and with that would suggest working with console projects to start such as the following. This project when reviewed and studied will increase your knowledge of working with Visual Studio and C#, I wrote this and note the project is in a repository with 70 other console projects which include several projects for creating dotnet tools.
Once comfortable with working with console projects, learn how to write unit test.
Next up, decide on a architecture e.g. web, desktop or mobile. In regards to desktop, my recommendation is to only use windows forms project for project that you use and not for others, if designed for others look at WPF and MAUI (which also is for Android and IOS) .