It is necessary to learn c or c++ or which language.

Answer 1

It addicted of your purpose of learning programming.
You can learn HTML, CSS, JS, after PHP, node.js etc if you want to become web developer.
You can learn C++, C, C# etc for development mobile apps for example.
You can learn Python as server side of sites or as language for the analisis of given...

Answer 2

Depends on your goals.