The drain plug washers are available at local auto parts. I like the fiber type. Just don't over-tighten the drain plug.
Filter location...when you drop the main pan it will be staring you in the face. Two bolts hold it in place. Very easy to remove/replace. Make sure to buy your gasket a few days in advance. It will come folded in half...unfold, place on flat surface and place something flat and heavy on top to flatten it. It will make the job a lot easier.
Also be sure to read the refill instructions in the manual. Filling is done hot with engine running and you must cycle through the gears.