I just need help to figure out the following: Should all extensions to be used in a Dreamweaver website should be installed prior to been developed? Is it ok to install a new extension while the site is been developed? I tried installing the Parallax Slider while developing my website and it became a total mess. Newbie here!Thanks for your help!

Hello Irmarie,
There is no any 'right' order to use the extensions. You can install and insert them in any time of your site development process.