Q: how I delete my name administrator in my macbook air?

You must have at least one admin account on the computer. If there is another admin account already you can either delete your account or you can turn it into a standard account by launching System Preferences and selecting the Users & Groups tab. Click on the garbage can in the bottom left corner and enter your password. Then click the option that reads "Allow user to administer this computer". The checkmark should be gone. Now reboot. If there is no other admin account you'll need to make another account (or select another user) and put a checkmark on the option I referred to.

It occurs to me now that you might be asking how to change the admin account name. If so, read this article.