Just don't dedicate your whole performance to mistakes, like that Pink Floyd cover you posted XD
Of course, but that means you actually knows how it's supposed to be played, and then you make a few clams or clunkers. I mean that one. I mean that Pink Floyd cover, they won't ever sound the same at rehearsal no matter how much they practice. They play the wrong notes, and wrong timing all of the time, and can't tell which is which. They can't even tell the right notes from wrong. Or timing. No matter how much they try to hone it.
The most "nervousness" for playing clams or clunkers live, is often that your adrenalin runs havoc with you and speeds you up, and especially with the drummer, that you count in the tune way too fast, and thus haven't practiced at that speed, and it's not until then those mistakes, and clunkers floats up to surface. But for everyone then.
As a band, all in all, you have nothing to fear, and you have nothing - really - to try to fix, and hone in. The small nit picky details, are just such things that will eventually just settle with playing more gigs. Because you yourself as a band, clearly knows where to focus, and on what to hone. And if you were nervuos as almost wetting your pants, that singing voice of yours - well - if that was any nervousness in any of that singing voice of yours, I would be become frightened of your talent, when that voice is sang without any wavy nervousness! You could sweep the floor with most of "Americas got Talent" contestants, if it came to that. I don't think you have to ever ask for anyone for guidance, or what some other people thinks of you. Not here at TB at least.
I can only wish you good luck, and you've definitely come off with a great start!