You can use any of the icons listed here : https://transvelo.github.io/pizzaro/pizzaro-icons/ or http://fontawesome.io/icons/
If the icons you want is not listed here you can generate your own custom icons from IcoMoon : https://icomoon.io/ or Fontastic : http://fontastic.me/or any other icon generator website. Once you’ve generated your custom icons, you will have to add them to your website. We have explained the process here : https://www.youtube.com/watch?v=hkCO2fWT7Sg