Really? You called Adobe support and they said they'd send you a tutorial? Usually those guys can find their posterior in the dark using both hands only on very good days. I think you're smoking something on that one.
What kind of flashing light? One that rotates, like the ones on old cop cars? Like the "12:00" that keeps flashing on your grandparents' old VCR? Like a round LED that flashes on and off on your alarm clock? Please elaborate.
I'd do that in After Effects (or even Photoshop), but in PremierePro here's how I might attempt it:
1. Make a colored solid (can use a black solid, then use the effect: Change to Color to make it the light hue of your choice)
2. Use an elliptical mask shape to make the light shape
3. Animate the Opacity Setting and trim to duration of a blink.
4. Use liberally in the timeline of this sequence: (copy paste ugh)
- Copy the video clip you've just made (blink layer)
- Target the same track (or a separate loop track layer) : See Target Video Tracks / Adobe helpx
- paste paste paste paste!!!.....
Premiere Pro is terrible for creating motion graphics, hence After Effects
I don't know if PremierePro even has a feature to easily allow you to loop the blink once you've created it. (You could try TimeRemapping back and forth with keyframes, but that is equally painful)