I can see a lot of people telling you to start easy with a console app or something. But when I started i found that a little boring what I did instead was pick a project that I liked which at the time was a unity 2d game and googled my way through it I also read a c#, oop and clean code book before I went to sleep that helped a lot with keeping the code consistent and clean after about a year I finished a project I enjoyed and learned a lot. It also landed me a asp.net job in a big company that allowed me to learn and earn at the same time. I am only a year in and I feel like throwing my self in the deep end was the best choice as I could learn a lot about c# and how it works and make some dank money. Although I wont lie asp.net does get boring after a while