2008 Suzuki XL7 Noise

Hello there! I have a suzuki 2008 xl7 I bought this used but it seemed in good condition, but after 4 months that I bought it I had problems with the A/C and it was replaced. But after 3 months of that repaired I noticed a noise that is seems to come from the serpentine but it is not always and it appears when the car has been driven a mile o more it appears and then dissapear.
Also today when I was parking the car it made a sound as rattling from the defrost area (windshield). Somebody could help me, what I could do? Thanks