The Premiere screen is divided into four main areas - Preview, Sequence Viewer Project and Timeline.
Two small areas - Tools and VU.
The lower left of the screen is your Project window Browser, which is like a file cabinet for your project within which you put your media files - audio, video, still pictures, and sequences/timelines.
Just above the Browser is the Source Preview window, where you can display and play individual video clips you drag from the Browser.
Below the Sequence Viewer is the Timeline, where you assemble your video and audio clips into a sequence to create a movie.
If you drag a video clip that also has two audio tracks from the Viewer into the Timeline, it will be displayed in the Timeline as a single light blue horizontal video track, with two separate darker blue horizontal audio tracks underneath.
Press the I Key (for IN) at the desired point where you want your clip to start playing. Then hit the O Key (for OUT) at the point you want your clip to end. You will see brackets appear in the window at the points you pressed the I and O keys.