What is the most logical next event?

How to create a coconut volcano
Choose a space that is easy to clean.
This is a messy project so find an area that can cope with getting a little messy, or work in an area that can be covered thoroughly with newspaper (such as the kitchen counter or table). You can skip the messy newspaper if you do the experiment outside on gravel.
Another suggestion is to do it in the bathtub (during a bathtime is even better since the lava will start to change the color of the bath water). Put some baking soda in a small cup.