can someone explain to me what the advantage is of having the methanol option on my lumina. what can i do with it and where can i get methanol in southern california?

IIRC, the methanol option is for emissions in California. If I'm right, then I wouldn't consider that an advantage.

can someone explain to me what the advantage is of having the methanol option on my lumina. what can i do with it and where can i get methanol in southern california?

The advantage or lack thereof is yet to be proven.
Your car is known as a Flexible Fuel Vehicle or FFV. It will run on M85 or regular gas automatically. M85 is 85% Methanol and when you fill up with this fuel a sensor automatically adjusts the fuel control to burn this fuel. You can mix the 2 fuels if you like.
Flexible Fuel Vehicles were mostly purchased by Government Fleets to get a lower cost/ mile vehicle.
Most Agencies did not renew them when it became replacement time.
They still make them but now are called FFV and use E 85 for Ethanol 85%.
Ethanol and Methanol produces less noxious emissions than Mogas and regular 87 Octane fuel does.
Bob