Load the beep on the timeline and zoom in far enough for it to stretch across the entire screen. Identify the attack, sustain, and release of the beep. You'll see that the at the beginning the beep may change in some way such as fading in or have a sudden peak. After this will be a relatively constant section until the release, at which point it will probably fade out rather quickly. Highlight as much of the constant sustained section as you can, being as careful as possible to have the start and end points of the highlight occur where the waveform crosses the centerline, and the same direction at both ends, either going up or going down. Ctrl-C to copy this section. Turn on ripple edits and place the cursor at the endpoint of the section you previously highlighted. Press Ctrl-V to paste. The section you copied will be added before the release at the end. If you've done this carefully enough it will sound like a continuous longer beep. Repeat the Ctrl-V as many times as necessary to make the beep as long as you want it.

Two ways to shrink the video: Use Pan/Crop and drag the cropping rectangle out larger than the video. Or, use Track Motion and drag the video rectangle smaller. In either case you can then move the frame around to position the smaller video where you want it to be on the screen.