Override Admin menu icon

One way is to use the admin_menu hook to insert CSS with your selection of menu icons (which use the DashIcons).

The googles show this recent result: https://swapnil.blog/2018/06/25/how-to-change-wordpress-admin-icons/ .

Here’s some code from there; you’ll just need to figure out the CSS for each menu item – use your Developer inspection tools (F12, usually) to inspect each element to find it’s CSS class:

function replace_admin_menu_icons_css() {
    ?>
    <style>
        /* CSS code goes here */
    </style>
    <?php
}

add_action( 'admin_head', 'replace_admin_menu_icons_css' );