First of all there is no such thing as a stupid question. That's how we all learn.[asking questions] I think changing your own oil is a good step in trying to do alot more of regular maintaince to your pathy. I work on all makes and models of pretty much everything you can think of all day long, 6 days a week, for close to 20 years . I love it when people take the bull by the horns and try things themselves. I would recommened buying a copy of Haynes Repair Manual for your specpic year, make and model. I 've been a mechaic for almoust 20 years and own my first Pathfinder. I love it, and will never own anything else sgain. I'm going for 500,000 miles before
any engine work.359,000 so far. Oh yah, the oil pan is the closest to the front of the vehicle. It's probably a 14 mm wrench to remove the drain plug. Good luck man, don't feel stupid for asking questions.