Answer 1

Gael it depends, some courses are quite long, and some are just really short. Learn at your own pace. You can get an idea of how long the courses take if you do some basic math too.

For example, the python developer course has around 70 lessons with quizzes (excluding the ai lessons).

If you do 1 lesson a day, it will take you 70 days to complete the course

If you do 2 lessons a day, it will take you 35 days to complete the course

If you do 3 lessons a day, it will take you 23 days to complete the course

If you do 10 lessons a day, it will take you 7 days to complete the course

Assuming you actually stay consistent.

Answer 2

there is no public data on it

Answer 3

It's getting more interesting