I think you first need to learn how to program in C# first.
Then you learn how to do GUI programming using C#. You seem to be leaning towards using WinForms. Personally, WinForms should only be used for maintaining legacy projects, not for greenfield projects.
Then you learn SQL. Better to do this straight up without any C# or ADO.NET first. Just use SSMS directly.
Then you learn how to access databases using C# using ADO.NET. (An alternative is Entity Framework which many will recommend, but I can't personally recommend.)
And then you learn how to put all of that together into your program that is your goal.
Any other approach (including asking ChatGPT, CoPilot, or Gemini to write the code for you) will be spoon-feeding and not lead to any deep learning if you are a beginner. Any you have experience with other programming languages including SQL, and are already familiar with databases and GUI programming, then this might be a viable shortcut.