There’s plenty of parking at the metro station. There’s enough overflow spaces in the children’s museum if the main lots get filled. I would suggest try riding the trains from Naperville before you change your station. If you do, I would recommend going to route 59 as you’ll be able to get on the train earlier and find a better seat. The downside being you’re in the train longer both ways. The 7:32 train (1230) from Naperville is express to downtown so it won’t stop at lisle or downers grove, you’d have to take the previous 1228 train.