Help with school sleeping schedule?

Okay well this year I am starting high school. School starts at 7:30 which is not what am used to, I am used to school starting at 8 so there's an adjustment there. So to have enough time to get ready and stuff I think i gotta wake up around 6 so I can shower and dress and stuff. So like when Do you think is a good time to go to sleep? Me sleeping is weird you don't know if its gonna take 15 mins- 2 hours for me to finally fall asleep. Sometimes it feels like I have insomnia. And even last year when school began at 8 I was like late for homeroom everyday. But the school is ALOT closer to my house now so I can run. And another thing I herd if your late too much they take off credit!!! so....help?