With the fires in California causing air pollution, will a whole house humidifier help eliminate air pollution within the house?

Not particularly. A humidifier functions primarily to add moisture to the air that is removed by the heating unit of a furnace, or separately as a stand alone unit. While some wick based units can trap some airborne debris, it should not be considered a pollution filter. Enough air bypasses this process that a separate filtering system is needed to avoid such particles.
HEPA filter unit. A HEPA filter unit may be helpful and keeping the windows closed.
Drink fluids and stay well hydrated. .