Hi Lena-
First off, don't worry. The most important thing to remember is to keep it simple and use the colors and products that work best for you. Always start with the basics like yellow-based concealer, foundation and powder in your skin-tone-correct shade. Begin by applying concealer at the inner eye corners. Blend a sheer, oil-free foundation over your face or just to where needed to even out skin. Set foundation with Face Powder for a natural, velvety finish. You mentioned your braces, the good news is they're not forever and they'll make your smile even prettier! I suggest focusing on the eyes and keeping the lips simple. On eyes, use a soft shade like Shimmer Wash Eye Shadow in Sterling on the lid and a coat of Thickening Mascara in Black on lashes. Finish with a slick of Lip Gloss in a neutral shade like Buff.