How do I troubleshoot configuration settings to know what's right for me?

Hi! I created (and recreated) multiple droplets because somewhere along the line I had issues connecting to my droplet via ssh. Most recently, I followed these steps in creating a new server: 1.https://www.digitalocean.com/community/tutorials/initial-server-setup-with-ubuntu-18-04 2.https://www.digitalocean.com/community/tutorials/how-to-install-linux-apache-mysql-php-lamp-stack-ubuntu-18-04#prerequisites 3.https://www.digitalocean.com/community/tutorials/how-to-install-and-secure-phpmyadmin-on-ubuntu-18-04

I am currently stuck on the third link, I am unable to connect to mysql despite having tried all the passwords associated with this database. My assumption is that I may not have fully understood how the mysql_secure_installation works from link number 2. Any assistance would be greatly appreciated!