How to develop locally from a live Wordpress install without overriding most current posts?

Hi Andrew, All Wordpress content data is stored in the database - including your permalink structure - posts, pages, comments, etc. Those are only overridden from the dashboard or by modifying them in the database(very careful). The FTP folders on the other hand contain all the structure and layout of your site: including themes, plugins,and many core Wordpress folders/files ( stay away). Those folders contain all the necessary structure you need to design and develop/code your website. As a developer You will be mostly working under the WP-content folder:( one example is the Themes folder) When you are developing a theme you create all your structure (HTML/CSS/ Javascript) like you would normally , than you would use the famous Wordpress query to loop through your post or pages and echo your data from the posts or pages (title, content, excerpt, etc) using Wordpress functional tags, ex:the_title(), you can think of them as variables or functions that holds your data content and are changed dynamically depending on the page or post you are.

I hope this can help you ! Thanks