Welcome to the forum, Jean. There are lots of good airbrushes. Everyone has their favorite. You can hardly go wrong if you stick with a name brand. The main thing is to understand how it works and learn how to clean and use it. Maybe something on my website will help. I think most modelers would recommend an internal mix double action airbrush. But, there are those who do really nice work with simple single action external mix brushes too. Be sure to consider how easy it is to get spare parts. If it is your first airbrush, I would not recommend getting a nozzle smaller than .35mm. A .5mm would be even easier to learn with and give a little wider coverage.
Good luck with your choice, and if you have problems, you can get good help here.
Don