I found this code on another post in regards to making modifications to the Account Details page but I don’t know how to modify it to do what I would like. Instead of adding 2 “favorite color” fields I would like to display a users profile picture and a button to upload a new profile picture. I have a shortcode from the One User Avatar plugin that has it all built in. The shortcode [avatar_upload] is a stand-alone uploader for users that are logged-in. Can the code below be modified to do what I’m attempting? I would also like to add this functionality to my Registration Form if possible.

// Add the custom field "favorite_color"
add_action( 'woocommerce_edit_account_form', 'add_favorite_color_to_edit_account_form' );
function add_favorite_color_to_edit_account_form() {
    $user = wp_get_current_user();

    // First Field
    ?>
    <p class="woocommerce-form-row woocommerce-form-row--first form-row form-row-first">
        <label for="favorite_color"><?php _e( 'Favorite color', 'woocommerce' ); ?>
        <input type="text" class="woocommerce-Input woocommerce-Input--text input-text" name="favorite_color" id="favorite_color" value="<?php echo esc_attr( $user->favorite_color ); ?>" />
    </p>
    <?php
    // Second Field
    ?>
    <p class="woocommerce-form-row woocommerce-form-row--last form-row form-row-last">
        <label for="favorite_color"><?php _e( 'Favorite color 2', 'woocommerce' ); ?>
        <input type="text" class="woocommerce-Input woocommerce-Input--text input-text" name="favorite_color2" id="favorite_color2" value="<?php echo esc_attr( $user->favorite_color2 ); ?>" />
    </p>
    <div class="clear"></div>
    <?php
}

// Save the custom field 'favorite_color'
add_action( 'woocommerce_save_account_details', 'save_favorite_color_account_details', 12, 1 );
function save_favorite_color_account_details( $user_id ) {
    // For Favorite color
    if( isset( $_POST['favorite_color'] ) )
        update_user_meta( $user_id, 'favorite_color', sanitize_text_field( $_POST['favorite_color'] ) );

    // For Favorite color 2
    if( isset( $_POST['favorite_color2'] ) )
        update_user_meta( $user_id, 'favorite_color2', sanitize_text_field( $_POST['favorite_color2'] ) );

    // For Billing email (added related to your comment)
    if( isset( $_POST['account_email'] ) )
        update_user_meta( $user_id, 'billing_email', sanitize_text_field( $_POST['account_email'] ) );
}

I don’t know how to write my own code. Sometimes I’m able to edit code that exists if it’s not super complicated.