Please don't hate...

I don't know where to put this question. I'm only 13. My school teaches sex ed when kids are 12. My mom refuses to let me learn about my body and stuff and she won't let me go to sexed classes. I started my first period not long ago and she won't teach me anything. I got this app to track it. What do I have to know about periods? And can I see a diagram of a vagina to learn? My mom keeps a block thing on my phone so if I try to search it up I'll get in trouble. Please help and don't be mean to my mom.