How would you create a stencil for use on a car?

I’ve never painted cars before. I painted a lot of models when I was a kid so I know some of the concepts. With respect to all the steps for painting the car I will watch the appropriate tutorials that cover the different layers, paint types, equipment, sanding, etc.

I want to be able to paint stencils on my car. It doesn’t have to look professional.

I want to make simple silhouettes and letters. The more videos on how to do it the more confused I get.

• Do you / can you use regular paper as the stencil?
• If you use spray adhesive to hold the stencil in place what type do you use?
• If you use vinyl how do you know which type of vinyl to use? There are so many different types and a lot of them are for iron ons. Few seem to be specifically for stenciling
• Is an automated cutter like those made by Cricut a good tool for the job? They seem like a small price to pay for the time and attention to detail savings.