Short buzzing noise with acceleration /2006 SER Altima

145,000 mi—06 Nissan Altima /auto trans Sometimes when shifting, it lags. With fast acceleration, there’s a short sounding buzz/whine for a split second I’m Leary of taking it to a dealership, I don’t know if I can trust them to not rip me off. I’m a woman, and I’d like to educate myself before taking it somewhere. Thanks for the help!