If the pilot light is out on your furnace, please call PG&E at 1-800-743-5000; they will send a technician to re-light any gas appliance free of charge.
If your unit has a central heating system then it is your responsibility to change the furnace filters once a year. A clean filter will help the furnace run more efficiently. The filter is located in the large cold air return grill. Remove the old filter and take it to your local hardware store to purchase a replacement of the same size.