Can you shoot 38 Special plus P ammo in a 38 caliber pistol?

Depends on the pistol. If there's nothing about this in the owner's manual, or there is no owner's manual, you should contact the manufacturer for clarification on this matter. If you're unable to do this, a gunsmith should be able to determine this for you. .38 Special +P is .38 Special ammo, but with a higher powder content, which generates higher chamber pressures. Older .38 Special revolvers which were manufactured before the advent of the .38 Special +P cartridge did not have to be mindful of this when they manufactured their revolvers.