How to contact a potential supervisor when I don't know if I am a good enough candidate?
I'm currently looking for a PI to take me as a student ina PhD program. So, I've contacted the student's affair office and they told me to introduce myself to the PI like this:

Hi Professor ABC,
My name is X and I am currently doing BLA BLA BLA at the Z Institute. I am interested in applying for a PhD at BLANK in the area of BLANK and was wondering if you were interested in taking on more students/have room in your lab for me.



Simple as that, he will probably ask you for a more detailed profile of yours with your cv.

Good luck!