Pimp my Log is a PHP-based web GUI for viewing log files on a given server. By default, it is installed on Drupal VM, and you can access it at the URL http://pimpmylog.drupalvm.dev/ (as long as you have a hosts entry for that URL pointing at Drupal VM's IP address!).
By default, it will find the default Apache 2 access.log and error.log files, but it will not find other logs, like MySQL or extra Apache virtualhost logs.
When configuring Pimp my Log (on the first visit to the pimpmylog.drupalvm.dev URL), you can add extra paths in the UI, or you can add them after the fact by manually editing the configuration file, which by default is stored at /usr/share/php/pimpmylog/config.user.php. You can also delete that file and re-configure Pimp my Log via the web UI.
Some log files you may be interested in monitoring:
/var/log/apache2/access.log/var/log/apache2/error.log(this log will show Apache and PHP notices/warnings/errors)/var/log/apache2/other_vhosts_access.log/var/log/mysql.err(MySQL error log)/var/log/mysql-slow.log(MySQL slow query log)/var/log/syslog(enable the Drupal syslog module to route watchdog log entries to this file)
For MySQL logs, you might want to read through the PML docs on MySQL.
It might be necessary to grant read permissions to the other group (e.g. chmod o+r /var/log/mysql.err) on some log files in order for Pimp My Log to be able to parse them.