How many times i must learn Curses for i can do codes on the code playground?

Answer 1

As many times as you need to. It'll be better to stick with your studies and focus on that; right now you're being distracted and this time could be spent learning further. Programming isn't something you learn overnight and master, it takes a long time to become a great programmer, but it's worth the time and effort placed into it.

Answer 2

You can start with the samples in the courses. It are working programs you can try and change.