If you insist on trying it by yourself (NOT recommended) I have a few tips:
Option A:

1. Go to a club and get one of the members to test fly it to trim it out first. This will remove all doubt about the airworthiness of the plane, and eliminate all excuses about mechanical issues when you tell your friends about the crash.
2. Find a friend with a video camera to videotape the flight and spectacular crash that will soon follow.
3. Wear a hardhat.
4. Go out to the desert, miles from any buildings or people. These planes can easily kill someone.

Where in California are you? If you live in or near San Diego I can recommend a club close to you. If you're near my club I'll do the test flight for you.

Your wifes heart was in the right place, and that Extra is a fine plane, but if you try and fly that by yourself you'll certainly lose it on the first flight.

Option B:

Find an experienced pilot with a buddy box to take you up a few times and see if you get the hang of it right away. If there is anybody out there that has learned how to fly with an Extra 300, I've never met him, but maybe you are that one-in-a-million that can prove us all wrong. (I really doubt it).

I started out just like you. I took my .20 size Cub to the local club and the members took me under their wing. They test flew my plane for me, let me have the sticks for a few minutes, then explained that there was basically no way I could learn on this plane. I swallowed my pride and bought a proper trainer. Your Extra, in the hands of a beginner, is MUCH harder to fly than a Cub.