Loading jQuery correctly causes JS issues

Hello everyone,

I recently discovered that I should be using jQuery that comes pre-installed with WordPress as opposed to linking to an included one in my theme using this code:

<?php add_action( 'wp_enqueue_script', 'load_jquery' );
function load_jquery() {
 wp_enqueue_script( 'jquery' );
} ?>

The problem is I get the following error message with a slider that I’m using undefined is not a function (evaluating '$('.slider').unslider()').
Here is my JS code:

jQuery(function($) {
	$(function() {
		$('.slider').unslider();
	});

});

Any help would be appreciated! PS: I’m not very good with JS/jQuery so please explain things clearly.