How to edit my account section in WooCommerce checkout?

Solution:

You can use woocommerce_checkout_fields hook

https://github.com/woocommerce/woocommerce/blob/4.1.0/includes/class-wc-checkout.php#L265

• Get an array of checkout fields.

Add the following code to functions.php

// Add field
function filter_woocommerce_checkout_fields( $fields ) {    
    $fields['account']['billing_email'] = array(
        'label'        => __('E-mailadres', 'woocommerce'),
        'required'     => true,
        'type'         => 'email',
        'class'        => array('form-row-wide'),
        'validate'     => array('email'),
        'autocomplete' => 'email'
    );

    return $fields;
}
add_filter( 'woocommerce_checkout_fields' , 'filter_woocommerce_checkout_fields', 10, 1 );