Reading your code, in the render method, you might be the victim of an errant cut-and-paste. You have an unmatched left curly brace because of this line:
{this.state.display &&
and you also have a bunch of JSX outside of your return() statement. My best advice is just reset the code and start again. I’ve had to do that few times now in the React lessons myself.
This creates another problem. Adjacent or sibling divs. One option is to return an array and separate the divs with a comma. Make sure to add a key prop to each item when returning an array with React. Otherwise you will get a warning in the console.
Sorry for the long explanation but I know learning React is a never ending process and somethings knowing these things in detail is helpful. These types of conditionals I find really useful. Good Luck.