desperately in need of makeup tips

did a photoshoot for a small clothing brand recently, this was my first time and damn I got humbled real quick. i spend all my money on skincare, and I don't even own a mascara, any tips on how to find my shade, everyone talks about finding your undertone, but I'm having so much trouble with it, why does it feel like the undertone of my face and hands are different. also my skin is super sensitive and acne prone, so I never wore makeup incase it triggered a break out, any recommendations for makeup that isn't comedogenic.