Hi, it really looks like normal grunge. As mentioned the bolt is just for the bell housing plate. If it was from the tranny input shaft ( a seal, and or a gasket) your clutch would be slipping. As a new owenr, I would fill, change, check a lot Especialy Brakes and safety stuff. I would pull al the wheels and check everything about the brakes first. Also get a Chiltons manual and read it and read it. I would drive on. Good luck