How do I no if I have full custody of my children, there father and I divorced 10 years agp he has ccess every other weekend up until 5 years ago and doesn't even contact them. My children do not want him to be able to access school records as he doesn't both and I want to have them upset

Was the current order modified by the courts? If not its not likely that you have full custody.

I don't think so I no that he was granted access which he never kept up and moved 100s of miles away but other than that I'm not sure. How wld I find out?

Look at your original paperwork. That should tell you. Since it hasn't changed.