Edit in JSFiddle

var myTween = new TweenLite.to('.box', 7, {width:100, height:100, paused:true, delay:2});

$('.btn_start').on('click',function(){
	myTween.resume();
})

<button class="btn_start" type="button">Start!</button>
<br><br>
<div class="box"></div>

.box{width:50px;height:50px;background-color:#000}
.btn_start{background-color:#c0b8ff}