By default new scenes you create should already have 2 audio tracks added.
If you are trying to add new tracks to an existing scene, just right click anywhere in the audio track portion of the scene director and choose "New Track". If you aren't seeing the audio track portion of the scene director you may have disabled them from view. Click the "down arrow" button in the upper left of the scene director (to the left of the frame number) to open the scene director menu, then go to the "Show" menu and make sure Audio Tracks is selected to be shown.
#XPression