What kind of feon does it use and how much pressure should there be?

Have a certified mechanic perform this service. Your car originally may have come with R-12 Refrigerant, or it may have been retrofitted to R-134A in the last 14 years. Regardless, you don't want to mix the two in the system. Pressure capacity must be monitored with an A/C manifold and gauge set, and will be different depending if R-12 or R-134a is the specified refrigerant.

Thank you