Which would be better row 1 or row 3 (row 2 is taken already) on a NWA airbus 320

Row 1 is a bit cramped to the bulkhead but you do not have anyone leaning back at you. Much more leg room in 3 though.

Disadvantages of row 1 relative to row 3: If you have a small carry-on piece that you need to access throughout the flight or at landing, take row 3. Purses and briefcases must be stored in the overhead bins during takeoff and landing if you sit in row 1, but there will be no bin space directly over you because of safety equipment. The substitute for back of seat pockets in row 1 is too small to be very useful and might be hard to reach when seated. Compared to row 3, the aisle person in row 1 is especially likely to be hit or stepped on when others board the plane. If you have extremely long legs, you would probably be more comfortable being able to stretch out and put your legs under the seat in front of you.

Advantages of row 1 over row 3: A further advantage of row 1 is that it's easier for the person in the window seat to get up. As mentioned above, it's easier for both aisle and window people to stand up in row 1 versus row 3 if the row 2 occupants recline. Row 1 will receive beverages first and might receive food first.

Overall, it's a matter of personal preference; there isn't much difference between different seats in FC beyond aisle vs window.