Be sure that your Sequence settings match your footage by doing this:
Or, right-click a media file and select 'New Sequence From Clip".
How do I choose the right sequence settings?
Getting Started with Premiere Pro CS6
Adobe Premiere Pro Help and tutorials
The definitive tutorial list in message #3 courtesy John T Smith:
Premiere Pro CS5-CS6 Reference
(.pdf 12 MB download)
If you are very new to Premiere especially CC its not very obvious how to start editing.
In CC after opening a new project you are not preseted with a New seqeunce window.
After importing some footage its not obvious to drag a clip into the new item icon. One is more likely to drag a clip into the timeline (with no seqeune).
These tutorials by Richard Harrington are the only ones which tells and shows you how to go about in CC.
Its not even mentioned in the Help.