Dennis' award winning poster template
You'll want to understand how layers work. They're simple.
https://helpx.adobe.com/illustrator/how-to/stay-organized-with-layers.html https://helpx.adobe.com/illustrator/using/layers.html
In this template there are 4 layers,
- A layer with guide lines to align to
- A layer for the header and footer
- A layer for the boxes that contain your content
- A layer for your content
Most of the time you'll probably want to hide the guide line layer, and lock all the layers except the one for your content