What is the best approach to learning c#?

Question

C++ / C#

I have been doing only javascript for 3 years, I went to the university and for the whole last year we studied assembler. Well, it's okay, I somehow survived, but now normal tasks have started and they said to use only c++ in projects || c#, I chose the second option. For one subject, you need to focus on drawing shapes and solving complex algorithms for optimization + visual solution, and for another robot with video, audio and real-time image recognition. There is also a subject on which there should be a group startup and its own project ( backend (api) + fronend application ), another part of the time will go there, taking it away from the sharps. Well, all sorts of labs ...
Well, for example, I'm trying to draw a coordinate plane, I went to 1 site, nothing, on the 2nd - too, ..., went to the documentation, and there:

public void DrawLinePoint(PaintEventArgs e)
{

    // Create pen.
    Pen blackPen = new Pen(Color.Black, 3);

    // Create points that define line.
    Point point1 = new Point(100, 100);
    Point point2 = new Point(500, 100);

    // Draw line to screen.
    e.Graphics.DrawLine(blackPen, point1, point2);
}

and how to actually work with pictureBox? Well, it is very difficult for me to get used to such documentation. And then I went to look for forums, so I was generally depressed :( The
question is how best to approach training in order to have time to deal with c #, given that every week you need to take something?