The "random[]" function can be called in several different ways to produce different kinds of random values. In your case, you want to select a random value from a list of possibilities and then supply that value to the "go[]" function.
The "go[]" function can navigate to cards by index (a number), by name (a string), or by value (a Card interface). We'll go with the latter. Within a script, all the cards of the deck are available as variables of the same name. Commas (,) between values are used to form a list. If we have cards named "cardA", "cardB", and "cardC", and we wish to navigate to one of those cards randomly when a button is clicked, we could give it a script like:
on click do go[random[cardA,cardB,cardC]] end
Does that help?
You might also find some of the examples in this tutorial illustrative: https://itch.io/t/3593043/make-your-own-chicken-generator