Critical WordPress Plugins
Auto Post Thumbnail – Creates post thumbnails automatically and is capable of creating retrospective thumbnails.
Really Simple SSL – For adding SSL certificates to a website, very easy to use. Important for SEO.
Smart Slider 3 – The best Photo Slider plugin due to being so easy to customize.
W3 Total Cache – This is THE WordPress caching plugin. Install this and set up some caching to improve performance and subsequently page ranking.
WooCommerce – The main E-commerce platform for WordPress.
Yoast SEO – Yoast is good for adding keywords, descriptions.