If I gotta pick someone up from their flight can I wait at the gate while they exit their flight or do I have to park somewhere until their ready to be picked up at the gate?

You have two options. 1. Park in the hourly lot (it's a couple bucks an hour) walk inside and greet them as they come down the escalator to the baggage claim area. Isn't it nice to be met that way? Or... 2. Park in the "waiting lot" about a half mile away from the terminal (follow the signs, no charge to wait) and have your friend text you when they get their bags and are headed to the curb. Remember, you CANNOT wait at the curb by the terminal. You WILL be told to drive out and re-enter the airport. So... How well do you like your friend? #1 or #2 ?

Usually around baggage claim and/ or loading area

Park or wait at gas station until they call you. Pick them up at loading area.