Hi Michael,
AtoM uses a number of page templates, modules, and components, so not everything is necessarily in a single file - for example, the main header bar in Atom is in a separate component. However, you can find the core of the homepage here:
So, from AtoM's root installation directory on your server, you could look in apps/qubit/modules/staticpage/templates/homeSuccess.php to find it. If you have followed our recommended installation instructions, then the full path would be something like:
- /usr/share/nginx/atom/apps/qubit/modules/staticpage/templates/homeSuccess.php
If you are considering making local customizations to your home page, I would recommend that you consider doing so as part of a custom theme plugin, rather than modifying the core homepage code directly. This makes it easier to maintain, and upgrade in the future.
I've supplied a lot of information on how to get started with custom theme plugins, and how they are organized (which might help you understand AtoM's overall organization better as well) in this previous forum thread:
There are also a number of other forum threads that cover theming - here are a few: