Han didn't seemed very surprised, or even impressed by Luke having a lightsaber. He rolled his eyes at Obi-wan's training style. Han's more use to luck given how things went down with the Falcon, so the Force as a thing doesn't mean much to him. That the Jedi were a thing isn't out of the question at all, especially given what Chewbacca has seen. Plus Han would have been a child during the Clone Wars. If one assumes that Corellia was part of the Republic, than he would likely have heard the various propaganda reels that ran during the war and probably from time to time about the Jedi doing one things or another. With the Jedi/Republic poster boy showing up from time to time....Anakin Skywalker, with the name Obi-wan Kenobi coming up now an again.