2005 Saturn Vue serpentine belt

Hi, I have a chirping sound that is getting louder from my engine, sometimes sounds likt a cricket too.
My mechanic told me it's the serpentine belt, it's drying out, should replace in the next couple of months? Is this normal for a vehicle with this mileage and does this seem like the right diagnosis?
Also, I had the brake pads replace reently because of a screech, the vehicle stops better but I still here the screech when the brakes are cold or wet, during the first few stops I make?
Thank you for taking my questions.