Best Western Spring House is a 2 minute walk from the Vatican museum entrance. We were quite comfortable there for a week. It's on the edge between a touristy area and more residential neighborhood, but an easy walk to lots of attractions and the Cipri metro station. From it you can get to the main tourist areas in just a couple minutes.

Saturday I would check into the hotel, dump whatever luggage you have, get a walking map and head toward the Piazza Navonna. Stroll around that area, have a drink at a sidewalk cafe, then head across a bridge into the Trastevere and find somewhere for dinner. That area seems to have a lot going on after dark.