Is it worth to prepare for Magento 2 Certification in 2018?

Question

I'm new to using Magento and wish to get into Magento 2 development. I've got some questions—

1. What languages should one learn before getting into Magento 2 learning/development?

2. What are some good online resources (for beginners) to learn Magento 2?

3. Is getting a Magento 2 certificates (Associate Developer and/or Professional Developer) worth it? The two exams together cost more than $450 and definitely demand a lot of time in preparation.

4. Whether these certificates are actually valuable in IT industry (as of 2018)?

Answer 1

I will focus on question 1. only.

Languages: PHP7 and ES6. SQL, not that much, although it never hurts.

JSON is a must, LESS is good to know.

HTML, XML, CSS goes without saying.

Knockout and RequireJS are very desirable to know.

On installation and deployment topic, it is a good idea to know git and composer.

Any CLI experience will do, although is good to be familiar with at least basic linux (cd, pwd, rm, cp, find etc).

On conceptual level, try to learn design patterns as much as possible and various paradigms like: SOLID principles, MVC patterns, Dependency Injection, Observers and so on.