If after a 3-day notice to pay or vacate has been served and an eviction has been granted, are we still allowed 30 days to vacate the premises?

You don't have thirty days to vacate after an eviction.  You will only be there until the landlord takes action to have you removed from the premises; for example, having the marshal escort you off the property.  If you haven't already done so, it would be advisable to find another place to live.