I have 12 chakra gates inside my body. So I’m still alive. You need to ask it from Gai sensi, I hear the subject is banned at the ninja academy.
these are some good sites on chakra-
But here is a Naruto guide on how to use chakra!- http://www.leafninja.com/chakra.php
i think there is only 7, but you could be right about the 8. anyways you cant open them like in Naruto, but trough mediation you can clannish your chakras, and after chakra cleansing you feel alot better.