Where is the power steering reservoir on a 1996 Buick Park Avenue with 3800 Series engine do you change belt supercharger of Park?

The power steering fluid reservoir on a 1996 Buick Park Avenue with a 3800 Series engine is typically located on the driver's side of the engine compartment, near the firewall. It's often a small, clear or translucent plastic container with a cap. Look for a reservoir with markings indicating "Power Steering Fluid" or a similar designation.

Regarding the supercharger and belt: The 1996 Buick Park Avenue 3800 Series *does not* have a supercharger. The 3800 Series II engine in that year used a naturally aspirated V6. Therefore, there's no supercharger belt to change. You'll only need to change the serpentine belt which drives the alternator, power steering pump, and other accessories.