If you need to display mp3 player with certain song on your product page in Prestashop, you can take advantage of HTML5 audio, supported in all modern browsers.
This article describes how to migrate Prestashop installation from your PC (localhost) to your domain. The reverce process is pretty much the same. On localhost I'm using XAMPP, which works well for Prestashop without setting any special parameters.
Learn how to create custom hooks in Prestashop 1.6 and 1.7 easily.
The overall speed of Prestashop site depends on many factors. The important part is performance and optimization of server, but you can also speed up the site by using certain settings and techniques.