not sure about install

Okay this may sound like a ridiculous question but i'm obviously new to all of this.  I wanted to install the cart to my site, but here is the thing, I currently am still building my site.  Actually the product pages are what I have left of doing my site but I thought that I was suppose to continue doing them, along with the cart, in my expression web 2 program before uploading everything.  or am I suppose to upload what I have and build my pages according to the cart?

You can upload/install nopCommerce (what you have done) to your site and then continue to create/modify product pages. You can upload them later

ok so i can go ahead and continue on with my product pages if I want to and then add the cart in later?

Yes