How do i turn on m fog light n my avalon toyota

SOURCE: Replacing 2000 toyota avalon fog light bulb

o easy enough just jack frontcar up use jackstand for safety now loo up under the bumper where fog lights sit depending on style fog light u might need to pull the whole assembly out or just twist the bulb not a hard task once u see it from underneath it is pretty easy

SOURCE: 2001 Toyota Avalon - Rear signals

Check the front lights. Usually if i flashes fast it indicate a bulb is out on that side.

SOURCE: 1999 toyota avalon horn works intermitely

I would suggest to you to have the spiral cable (or 'clockspring') replaced. This is the electrical unit that transfers power to the air bag, the horn and the cruise control.

It is located right under the seering wheel.

Your description of the issue indicates to me that your spiral cable is loose, and making intermittant contact. If the vehicle had an air-bag deployment, this cable-device should have been changed.

SOURCE: 2001 toyota avalon engine and vsc light stays on

You have to use a scanner and pull the code out that is causing the check engine light to come on. whatever code/codes you find are probably related to vsc light.
Good luck and keep me posted

SOURCE: 99 Toyota avalon starts but there's no dash lights

Did you check the fuses?