Make your stitches very small. The reverse side of your project should look like "chicken scratchin" . . . very very fine and short stitches, close together.
Since this is your first attempt to applique, do not get discouraged. It takes time and you will get better. I promise.
Remember when you are ready to press, place your work face down on a terry towel and press slightly. You can use steam. Do not scrub. You will be so pleased with your results once you have pressed.
Suzanne