At the bottom of the composition window there are a few options. Let's go over some of them.

The icon in the lower right hand corner of the composition you will find your guide options. These guide options are used to arrange your layers and  create compostionally strong images.  However these guides are not rendered they are only for preview purposes.

Guides-guides are used to align and arrange layers to. To remove guides choose view> Clear guides.

Title/Action Safe-video safe zones for standard video monitors

Rulers- Used to drag guides to the composition. to align and arrange layers to

Grid- A modular grid that helps you organize your layers and create strong compositions.

 A little further over to the right is the resolution button. You can reduce the quality down to Quarter. This gives you the ability to look at it and play back even faster but at a lower quality:

Next we will go over our Effects & Presets panel. The effects panel is a major toolbox full of effects to make your video look amazing! This panel gives you access to hundreds of effects that can help you create animation, correct color, or fix any number of problems with video or images.