Does the park still offers free entrance from 7:30 - 9am during pandemic? And do we have to be SF resident to get in free?

Yes there's free entrance during that timeframe regardless of whether you are a SF resident. SF residents get in free at any time

Yes it's free before 9 for anyone

The park is also offering free entrance to all on Christmas day (12/25/20) and New Year's Day (1/1/21).

Confirming community responses are accurate - thanks everyone