There are several different terminals. American flies into them all, so you need to know what terminal the flight will come into. You can google flights from Miami to DFW landing at 11:20 to find the flight number. Then it will tell you what terminal the flight is coming on at.
You can park in the garage and wait for your friend in the baggage area. You will need to know the flight number so you can find the right baggage claim to go to.
Thanks! Your answer is awaiting moderation.