posted by rfvv .
1. At Sora's school, the first period begins at 8:30 am.
2. The first class begins at 8:30 am at Sora's school.
3. School begins at 8:30 at Sora's school. Students should come to school by 8:30, and they should do self-study for 30 minutes. They take a break for 10 minutes. Then the first class begins at 9:10 am.
(Are they all grammatical? Would you check the sentences? Thank you.)
The only correction is that am is an abbreviation so it should be written a.m.