How bad of an idea is to delve into php in 2019? But since I have to, I would like few links on how web applications are made in php or it's frameworks such as laravel.

Depends on who you ask and if they've actually used php before.

The bandwagon would so Don't.
The devs that have been doing it for over a decade would so go for it.

If you like strict type languages, php is not for you, well probably not entirely although php7 does allow for it.
If you like the freedom and flexibility of a loosely typed language, it's fine.

PHP can be used beyond web without effort aswell so you aren't limited to just web.

Frameworks best suited:
Laravel
Symphony

The PsR (standards for language usage)
https://www.php-fig.org/psr/

Phpunit: for unit testing

And a good opening to getting started the right way

https://phptherightway.com/

I personally think PHP is still a good choice but I would only recommend use it with some framework now. Laravel or Symfony.

My personal opinion: PHP is still fine for smaller projects, where performance isn't an issue.
But since PHP does not have non-blocking I/O you will get much better performance from Go or Node.js backends, when I/O is involved.

PHP is still valid choice, even though there is so much flame against PHP in community. They still live in old PHP times.

I wount duplicate @C0D4 input, he is straight to the point. If you want easier framework for starters, I figured easiest for me to get started was Code Igniter. But its personal taste and consideration. I would say go for it, becouse PHP is to be honest quite easy lang to learn. Just be sure to sue php 7+ features like type hinting.

Please, do humanity a favour and type hint... allways. And if there is valid exception that you just cannot do it add in /** */ comment block types like "bool|string" for example.

Sure, won't hurt to know another language.
As for your resume, PHP's a waste of time