Leave it in "D."

Automatics do not have a clutch, they have a torque converter. It does not wear like a clutch.

Automatics were designed to let complete idiots drive a car (no offense to you, of course) and only need to be moved between "P" and "D." When you are out driving, leave it in "D," when you park, put it in "P." Nuetral is really only there for when the car is towed or needs to be pushed.