I am not familiar with Adobe muse but I will assume that you have a directory containing your site files. Your droplet will need a web server. The two most common options are Apache or nginx.

To install apache:

apt-get update
apt-get install apache2

To install nginx:

apt-get update
apt-get install nginx

If you installed apache, your default web root directory will be /var/www/html if you used nginx it will be /usr/share/nginx/html

You can use SFTP to upload your files using your root credentials. Filezilla is a good option for this and is available for Windows, Mac and Linux.