Javascript enqueued correct, yet cant get it to work.

I am making a custom theme, i have enqueued my js file as seen here:

function stage_script_enqueue() {
			wp_enqueue_style( 'customstyle', get_template_directory_uri() . '/css/stage.css', array(), '1.0.0', 'all' );
			wp_enqueue_style( 'customstyle2', get_template_directory_uri() . '/css/stage2.css', array(), '1.0.0', 'all' );
			wp_enqueue_script( 'customjs', get_template_directory_uri() . '/js/stage.js', array(), '1.0.0', true );
		}

		add_action( 'wp_enqueue_scripts', 'stage_script_enqueue' );

when i put the line alert(‘alert’); inside of the js file, it works perfectly fine, yet when i put this in it:

$(window).load(function() {
	$('#slider').nivoSlider({
		effect:'random',
		slices:12,
		animSpeed:500,
		pauseTime:2000,
		startSlide:0, //Set starting Slide (0 index)
		directionNav:false,
		directionNavHide:false, //Only show on hover
		controlNav:false, //1,2,3...
		controlNavThumbs:false, //Use thumbnails for Control Nav
		pauseOnHover:true, //Stop animation while hovering
		manualAdvance:false, //Force manual transitions
		captionOpacity:0.7, //Universal caption opacity
		beforeChange: function(){},
		afterChange: function(){},
		slideshowEnd: function(){} //Triggers after all slides have been shown
	});

    $('.hamburger').click(function(){
        alert('geklikt!');
        $('#tooplate_menu').toggleClass('slidedown');
    });
});

It does nothing at all, when inspecting the source code of the homepage, i do see my js file in there, but my slider and hamburger menu both do nothing.