How are product pages set up and organized?

Greetings!

I'm a little confused on how product posts are related to blog posts. I know they are separate "post types" but when on the product page the top left still says "HOME/BLOG".

How are product posts set up as far as on the WP site in general?

And also, how can I make every product page (new products page's included) include different elements/regions on the page like a sidebar, the main header, etc?

A couple more things:

- I would like to make the related products on each page not be displayed in a tab mode but at the bottom of the post by default.

- As well as the description for the product being displayed permenetely

I hope you can help!

Thank you
Ciro