I'm sorry you are having trouble talking to your child's teacher and accessing your child's school records. As a parent, even without primary custody, you have the right to view and access your child's information. If the school requires the custodial parent present- then ask the school to make those arrangements. If the custodial parent refuses, then talk to the vice principal or the school counselor about what arrangements can be made so that you can access and discuss your child's school progress.
If you are still at a standstill, ask the school counselor for recomendations on help from county resources to gain access to these records (possibly a childcare resources, sponsored by your local city or county.)
If that doesn't work- then it's time to talk to an attorney. Being part of your child's life means that you take an active interest in his/her school progress. If that is not allowed, then you need legal assistance to get this changed.
I hope that gives you some ideas on steps to take. Good luck.
Shirley Cress Dudley
MA LPC NCC FACMPE
Expert for blended and single parent families
Director of The Blended and Step Family Resource Center.