I am in the process of developing my first website on Visual Site Designer. I am wondering what I need to do to scale page elements by screen size. Can VSD do this or are the pages automatically fixed with this program?

Page sizes are static in VSD, set to whatever dimensions you choose.
If you keep your pages under 1000 px wide (centered) they'll show up fine for a lot of different browser sizes.
You can do a search on the forums to find out about creating separate pages for iphones, etc and how to link to them.

Some users are doing redirects to a mobile version of their site when they detect that a user is on a smart phone.