You're not short on choice when it comes to debugging a Drupal website.

You can install Devel and use Kint to print variables to the screen. Or you could use Web Profiler to add a toolbar at the bottom of your site to see how things are performing.

If you're looking for a proper debugger look no further than Xdebug. It integrates with a lot of IDEs and text editors and I'd recommend you try it out if you've never used it.

I recorded a webinar about Drupal 8 debugging which you can watch above.