Training https://code.tutsplus.com/courses/introduction-to-wordpress-plugin-development/lessons/how-this-course-works https://wpbuffs.com/wordpress-plugin-development/ SMS Integration https://wordpress.stackexchange.com/questions/264983/how-to-send-messages-when-a-customer-is-registered/265009 Create custom shortcode: 1. https://pagely.com/blog/creating-custom-shortcodes/ 2. https://codex.wordpress.org/Shortcode_API Add extra user fields https://www.cssigniter.com/how-to-add-a-custom-user-field-in-wordpress/ Add extra user fields in registration https://www.cssigniter.com/how-to-add-custom-fields-to-the-wordpress-registration-form/