Have to journalize this transaction in accounting class for the month of November

Received $500 in total for 4 monthly lessons that began on November 31

I think is like this:

Debit cash 500 and credit unearend revenue 500
Is that OK?

If you receive payment before the lessons started your journal entry is correct.

When you actually provide the lessons the journal entry will be:
Debit Unearned Service Revenue for $500 * 1/4 if provided one month of lessons 2/4 if two lessons, and so on.
Credit Service Revenue for the amount.