WordPress sorting posts by date and title using a dropdown

Here I put orderby attributes as option values – date and title.

<form method="GET">
    <select name="orderby" id="orderby">
        <option value="date">Newest to Oldest</option>
        <option value="title">Alphabetical</option>
    <button type="submit">Apply</button>
<form>

On the same page you can recieve select value and set as orderby attribute

$wpb_all_query = new WP_Query(array(
    'post_type'=>'post', 
    'posts_per_page'=>-1, 
    'order'=>'ASC', 
    'orderby'=> esc_attr($_GET['orderby'])
); 

Use your loop to show posts