Hello, no reservations needed, just walk into the visitor center and make your choice whether yoy would like to tube down the river or raft down, or simply hike through the Chasm. You could also decide to do the ropes course

A couple of hours would be plenty.

I would not take the baby on the raft. There is a safety reason for the 30 lbs minimum weight requirement. I would call the place to be absolutely certain.

Cost depends on what you want to do. The plain entry just let's you walk the gorge trail which ends with a short ride on the river and that's not too pricey. For the trips with ropes and stuff where you zig zag over the river between the cliffs the cost is considerably more. Do bring your own food and water. There is a snack bar but it isn't cheap. Check website for various prices.

Tubing is just one of many activities we have here at Ausable Chasm. If tubing swimwear is appropriate attire. Thank You

You would only need to remove your shoes, only the bottom of the raft is wet.

You can have hot dogs and sandwiches, little things like that. But maybe preferably pack a lunch.