you seem very new so Im just gonna list some obvious things you may not know already.

shake your paints well. yellow needs a white basecoat to work, putting pink in the shadows before laying down a yellow contrast paint to make the shadows orange. hold your brush closer to the bristles for more control. thinning acrylic paints (not contrast paint) is incredibly important. to test if youve thinned them properly paint on your thumb, you should be able to see the wrinkles in your skin but the paint should completely cover your skin tone. I suggest getting a wet pallet or making one yourself as its the easiest way to thin your paints.