An array is nothing but a list. A list of fruits, for instance.
If you're going to introduce arrays and objects to them, you probably have already introduced variables to them.
How do you store a single fruit?
var fruit = 'apple';
How do you store a lot of fruits?
var fruits = ['apple', 'orange', 'kiwi'];
You can perhaps tell them that whatever they have seen so far is simple enough to talk about types like integers and strings. But, to handle real life entities and represent them in code, you need an object.
var person = {name: 'Blah Blah', age: 24};