Disappearing icons used to create a form

Use icons for a drop-down type of menu (with logic).

Hello - I am not a coder at all but I do know what I am trying to achieve. I have icons that represent parent and child categories. For example: an event called Festivity and a to that event called Birthday. Another child could be Christmas. Icons will represent each of these.

When the user is asked is what type of Event, they would click the Festivity icon, which would then reveal the two smaller child icons (Birthday and Christmas). If Birthday was selected, the Christmas icon would disappear and change/be replaced by an icon that said Age?

To make it better, once each icon selection was made, that icon would disappear to be replaced by an underlying textbox with the field name it. In the end you would have a complete form filled out.