WP setup as cms

I’d like to use WP as a CMS for a website such as to be able to update certain sections independently.
Ideally, WP should be able to create [or use existing directories on the server], where it saves pages with sub-directories for pictures.
As I understand, you can produce posts and pages with WP. However, it looks like it’s mostly geared towards producing a single directory where all the posts are collected, under individual categories. It appears that you can’t save single pages under categories, that would mimic the structure of a website.
Using v.2.01, and very noob to WP, so please help!
Thank you,