It burns on the outside of my clitorios and there's a rash. What should I do

How old are you? Depending on whether you are old enough, call the doctor yourself or talk to your mom and have her take you to the doctor.

Have you used any new soap, or soap with scent while washing your genitals?
I am very sensitive and get rashes and burning very easily.
Try having a soothing epsom salt bath, stop using any soap unless it is a baby wash or female genital wash.
If it doesn't resolve you should go to the doctor.