I put a large sheet pan on the shelf below the loaf pan to catch any drips, so they don’t burn on the bottom of the oven. Typically it is not necessary; the loaf simply rises with a nice “bump” in the middle and there are no drips. But it’s better to be safe than sorry. Do not put the sheet pan on the same shelf as the loaf pan as that alters the baking time.
If you check the banana bread and the top is browned before the center is fully baked, put a piece of foil loosely on the top as it continues to bake.