It sounds like you are going to try needle turn appliqué? If that is the case, go for simple larger shapes with more rounded shapes. Tight inside curves and pointed leaf shapes are more difficult for beginners.
If you are talking about machine appliqué, it is fairly simple with the right equipment. I like Wonderunder for a fusible and buttonhole stitch for machine sewing it down. Good luck with whatever method you are using. There are a lot of good tutorials for both methods on the web.