How to become a Drupal developer?

Question

Drupal

I've been seeing jobs like this lately.
The level is very low. Studied Java.
What sources to study? Do I need to learn php first?

Answer 1

You need to know OOP and PHP at a sufficient level https://getjump.github.io/en-php-the-right-way/
The main resource is https://www.drupal.org/documentation.
You should start learning with Drupal 8 and don't waste your time on Drupal 7.