Install multiple apps on a Bitnami stack
This is not a direct answer to your question. If it wasn't long I'd post it as a comment.
Since you mention configuring a server is not your forte, I'd like to recommend you and other Drupal developers at any level of expertise, an alternative development environment to manage multiple instances of Drupal, and other websites in a Vagrant virtual environment:
Laravel's Taylor Otwell also created Homestead:

Laravel Homestead is an official, pre-packaged Vagrant box that provides you a wonderful development environment without requiring you to install PHP, a web server, and any other server software on your local machine. No more worrying about messing up your operating system! Vagrant boxes are completely disposable. If something goes wrong, you can destroy and re-create the box in minutes!
Homestead runs on any Windows, Mac, or Linux system, and includes the Nginx web server, PHP 7.2, PHP 7.1, PHP 7.0, PHP 5.6, MySQL, PostgreSQL, Redis, Memcached, Node, and all of the other goodies you need to develop amazing Laravel applications.

It certainly targets the Laravel developers, but I've been using it for most of my local development needs, whether they are Laravel, or Drupal (6, 7 or 8), or any other PHP website.
It makes it much easier to manage any number of websites with different PHP versions, different database needs, and custom hostnames in a single configuration file, to your liking either YAML, or JSON file.
I should mention that I'm not affiliated in any way with Laravel or its creator. I just really like my experience with Homestead so far, and wanted to share.
Go ahead and read its documentation, and install it globally on your machine. Set up a couple websites and give it a try. My guess is you'll have your sites up and running before you can resolve the issues with current Bitnami instance you have.