On Digital Ocean, assuming you did their fast install when you set up your droplet, the WordPress installation is located in /var/www
This is also:
- where your .htaccess file lives
- where you upload your .html file for Google Analytics
- where you’ll find the folder for uploading your theme (wp-content/themes/ThemeNameHere) – or where you can directly upload updates to its .php or .css files without having to re-zip the whole thing