I'll address a few of the most likely things people are going to say. I already did ask what I should do, to which my friend said "act naturally, be yourself" with myself being a socially awkward nerd who has a tendency to infuriate 7/10 people I meet. Yes, she realized this and rescinded "be yourself" to "be somebody else, somebody likable, who... just be like my girlfriend." Please do not encourage me to have her come out of the closet, her parents as I said, apparently comparable to the WBC. Yes, I did ask if it would be okay if I asked total strangers online for advice. Yes, I have met her girlfriend, we have similar interests and are friends/friendly, and I was apparently her first recommendation for taking her place in the "date." Yes, I did ask why to which I was told, "I have a good feeling about you" to which I responded confusedly and basically asked why, to which she responded, vaguely, at which point I started pulling my hair out, at which point she stopped me and said "that's why"
It's only 1 dinner, so I'm sure I can manage if somebody gives me some advice, plus I was promised steak and a "big" favor.
And I've only begun fucking with you people.
At the end of the day, it's all math.