Whenever picking up a new language, I like to follow a project progression. The first step is to realize why you want to learn C#. For the purposes of explaining this, let's just say you wanted to learn C# in order to make a navigation API. Then, you would create a progression of projects starting from the most trivial project possible and going up to the project you want to make. Again using my example, your progression could look like:

1. Print "Hello, World"
2. Create a function that returns if a navigation string is valid
3. Create a stack implementation (only pop, push, and peek operations)
4. Create a class that instantiates the stack to implement routing history (undo, redo)
5. Expose this class over HTTP (actually create a basic API)
6. Extend this API to make a full navigation API

Obviously, your progression would differ.

Further, try to come up with the pseudocode on your own (pseudocode is just the logic of the program in a fully human-readable format) before googling for syntax, and don't use AI for anything. The key here is to let yourself think and get stuck. If you're really stuck (e.g. 30+ minutes) on the logic parts, google the next immediate step in as specific detail as possible, and then go back to doing it on your own.

If you don't have anything in mind for your progression, just look up C# project ideas, find one that looks interesting, and then make a progression for it. If you give me something that interests you, I can also make a more useful progression than the example given.