Just wanted to mention that it is $10 per adult, $5 per child to go up the volcano path and to the ice caves. We went this past weekend and really enjoyed it, though! Wear good walking shoes, and if you have a little one who doesn't walk long distances on their own a lot, you may want to consider wearing them in a backpack style carrier. The path up the volcano is a fairly steep grade at some points, but completely cleared. It is a half mile up and there are markers along the way that goes with a guide they give you that tells you what you are looking at. It's a shorter walk down a different path from the store to the ice cave (it is a very steep staircase that has uneven steps, so again, hard to do with tiny children, you will want a hands free way to carry them so you can hold the rail.)
They do have ample parking and picnic tables you can sit at. They sell some snacks, but it's mostly just some sodas and candy bars so if you want something more sufficient it'd be better to take a cooler. They do have bathrooms in the store as well.