HTML & CSS, though are basics of Front end, are more than enough to create fast & responsive product based websites, used along with many online tools available in my arsenal, with Dribble & FreeFrontEnd I practically am never out of ideas. JavaScript and many useful JS Libraries like rellax.js, locomotive.js ,etc can make websites dynamic with ease.
I learned HTML, CSS, SASS, Javascript, SEO and Wordpress through a Udemy course by Juan E. Galvan & Nahid Akhter, certificate attached below.
I also learned basic Figma from YouTube, so I can work with UI/UX designers and make beautiful webpages. I also follow CSS GOD Kevin Powell and YouTube Channels like DesignCourse who share amazing content related to frontend. Make sure to visit my Portfolio (designed that myself, it sucks lol), and follow my other work.