BuddyPress.org

Hi
I’m pretty familiar with WP, but new to BP. I am trying to get BP installed and going and have come across a page that I am unsure about.

Making Your Theme BuddyPress Compatible Step Three Fixing Alignment

Is there a more detailed tutorial available than what is in the WP backend?
My confusion is here:
The instructions direct me to open my page.php file (which I have done), but I am not sure what I am supposed to be looking for within this file.
(You will need to change the HTML structure in the BuddyPress templates that you copied into your theme to match the structure in your page.php or index.php file. The files that you need to edit are as follows (leave out any folders you have not copied over in step two)
I’ve located the page and index files but like I said am not sure what to look for or copy, and then when it says try the easier step with the header, footer and sidebar I become even more confused on how editing these three files will change the layout. Any help or insight would be vastly appreciated.

Thank you so much in advance.