Great place to walk around! If the welcome center is open get a map so you can walk to the different numbered stations and read about the park! I recommend that you check their schedule for activities. They have a festival the last weekend of June that I highly recommend!!!
Words can not really describe this. To be standing next to an active Volcano is incredible. I recommend taking the nature walk with the Park Rangers there, it is a hike, so be ready for it. Make sure you have good shoes on, not sandals or flip flops. You will get to walk through a rain forest which will lead you around the crater. You will end up at a 3 way split. 1 way heads to the volcano overlook, 2nd way leads you through the sulfur path and the 3rd takes you back to the Ranger station, where you can take your car up to the overlook. The walk to the overlook is about 1.5 miles so be ready for a walk. Have fun!!!