I really want red hair like cat from victorious but dont know if i'll look good or not!?

Maybe you could consult your friends and family, but really stick to what you want. It's your hair not theirs! If you're not so sure, maybe do a softer red and then see how you like that. It is hard to get past people staring at your hair if they think it looks different, but hey, if you like it its fine and like i said it's your decision. We only get one head of hair, might as well have fun with it!