There is one Hobby Shop in Lansing, yet. "Just for Fun" (517 351 0313) in the Frandor Mall. It is very small and only a few train items. They rely on "special orders" for their train dept. There are a couple in Owosso, one, "Funny Pages" (989 725 9994) is very small also, same predicament as the Lansing shop. The other I've only heard about recently and don't have first hand info. Flint and Grand Rapids are about an hour from Lansing, and both have a "Rider's Hobby Shop" (Flint 810 720 2500) which have a nice train dept. Plymouth is also about an Hour and has a small O scale only shop, "Plymouth Trains." If you have enough time, the Detroit shops, between 1 hour and 1 1/2 hours from Lansing, are...
Wild Bills, 586 792 0530
P&D Hobby, 586 296 6116
Great Lakes, 586 254 1610
In Bridgeport, there is "Junction Valley" and they also have a quarter size railroad that may still be running, 989 777 3480.
You can "Google"/phone for hours and directions. Hope this gives you some ideas. As for just watching model trains "Chi Town Union Station" is a great destination... don't know if they'll be open yet (248 613 9471)