Help needed with site structure

I need help with how to use wordpress to architect and set up a site like the following:

No theme, it’s a custom build.

1) Digital products/e-commerce: (mysite.com/store/) Almost like a blog, with new digital products available for download every week. This will be the homepage. There will be an overview page, sorting functionality and product detail pages. No cart.

2) Blog. (mysite.com/blog/)This is a very straight foward blog. will be an overview page, results page (for categories and such) and full post layout.

3) About page (mysite.com/about/). This one’s easy.

My question is how should I architect this? Where does the styling code go for both of these go? Im used to using index.php and a loop to display posts and such, but this is different. Where would the code for displaying products go? I know i need a plugin or something too. I can figure out the code and such, I just need to know where to put it and how to tell wordpress to behave the way described above. Many thanks!