If you want hide content until complete loading, you need a loading page. To create loading page follow the steps.
Add below code after the <body> tag.
<div class="loading-page">
<img src="../animation.gif" alt="Loading..." />
</div>Add styles to your CSS file.
.loading-page{
position: fixed;
z-index: 999999;
background: #FFF;
width: 100%;
height: 100%;.
display: flex;
align-items: center;
}
.loading-page img{
margin: 0 auto;
}And finally add the jQuery code in your js file.
jQuery(window).load(function () {
jQuery(".loading-page").hide();
});