Bobeira is a colloquial Portuguese word that means 'foolishness' or 'nonsense'. It's often used to describe something silly, trivial, or a waste of time.
In the song, Ana Vilela sings, "'Tá de bobeira aquele que dispensa um amor assim" (He's being foolish, the one who dismisses a love like this). Here, it implies that someone would be silly or making a mistake to let go of such a special love, making it a charming and relatable expression.
"Pra Não Te Acordar" is about the specific, small-hours moment of watching someone sleep and being scared to break it. Ana Vilela opens right on it: "Sorte é ver você sorrindo" [Luck is seeing you smiling] "Enquanto você 'tá dormindo, amor" [while you're sleeping, love] "Será que sonha comigo? Eu não sei, mas não ligo" [Do you dream of me? I don't know, but I don't care] "E, pra não te acordar, eu nem respiro" [and so I won't wake you, I don't even breathe]. That last line gives the song its title, and it's the whole idea in one image: holding your breath because the person next to you is that good to look at.
The verses explain why the moment lands so hard. She'd basically given up on love before this: "Eu já tinha desistido dessa coisa de amor" [I had already given up on this love thing], "'Tava só me divertindo, mas você me ganhou" [I was just having fun, but you won me over]. There's a flying image tucked into the bridge too, "A gente voa junto, sim" [we fly together, yes], the idea that being tied to somebody doesn't clip your wings, it's what gets you off the ground. By the closing line she's stopped being clever about it and just says what she wants: "Quero que dure tudo isso" [I want all of this to last].