The most used programming language in sololearn

Answer 1

if you go to the website, and then courses, you can see how many people have learned a a course. If you want to know about the code playground, web.

Answer 2

It is difficult to define without official data. Even so, I would dare to say that one of the courses most taken by the community is HTML.

In CodePlayground it would be the WEB set, followed closely by Python (this according to what I've seen).