Hi,
I started learning c # about a year and a half ago. I initially read books and used UDEMY as a source of knowledge. I base my "exercises" on OpenNos for about half a year.
From my point of view this is a great option. You need to learn the basics, but then you will be able to master more advanced functions by adding various (more or less complicated) features to opennos files.
I would like to recommend "C# in the Nutshell". I belive it's the best book with c# knowledge for beginners, but for semi-advenced developers too.
greetings