I’m not much of a Joomla user myself but from some quick searching it appears that a quickstart package includes everything you need so this is what I would recommend.

1.) Create a droplet using the LAMP or PHPMyAdmin image (if you want to use a GUI to import/manage your database, use PHPMyAdmin, if you’re comfortable using the CLI, use the LAMP image).

2.) Upload your web files to /var/www/html (when connecting you start out in /root and will need to change up a directory).

Follow these instructions.

I would recommend this method over using our existing Joomla image since you’d be overwriting existing files and this could make the process more complicated instead of less.