If it looks smokey or if there are health advisories issued by the air district it is best to stay indoors. Wildfires have the potential to cause increases in Ozone levels which you may not be able to see or smell, keep an eye on the AQI and air quality data provided by the District.
Filter your air
If your area is being impacted by poor air quality keep your windows and doors shut. Run your central air conditioner or HEPA Air Purifiers. Keep in mind that evaporative coolers (swamp coolers) pump smokey air into the house. Consider using a portable evaporative cooler inside the house or seeking shelter at an alternate location, especially if heat is an issue.
Avoid activities that can increase particulate matter inside your home
Avoid vacuuming, vacuuming can cause re-suspension of particulate matter that has settled in flooring. It is best to avoid this activity during a wildfire to reduce your exposure to particulate matter. Avoid certain cooking activities like frying and broiling. Frying and broiling can release particles in the air that can degrade indoor air quality. Avoid using candles and incense, which again, can increase particulate matter in your home.