Really, what is a "typical girl?" Sorry for this tangent, but to me, a "girl" is 12 years old. I'm 52 and have had it drummed into my head since the 1970s that it is insulting to call a grown woman a girl, so I just can't abide by that phrase.
Anyway, I am not your typical woman, and I wouldn't think of a dinner hosted by a bf's wife at her home as a first date, but I think a slightly dressier version of business casual would work for dinner there. Nice slacks and a pretty blouse, with a little bling should do it. I would say not to wear anything that is uncomfortable or that you have to fidget with, if being there for dinner will make you nervous enough.
And I wouldn't wear ridiculously high heels if I were you, either, but that's me. Those kinds of "fuck me" shoes were originally made for lying down, not walking around, and I think women look like jackasses wearing them in the street. That's why I call them "Stupid Shoes." But I digress again.
As for your job interview, there are lots of resources on the internet for what to wear. Google is your friend.
Hot chick in the city.
Oh, oh, can't you see? Love is the drug for me. ~Bryan Ferry
"Love is that condition in which another person's happiness is essential to your own." ~Robert Heinlein