So when you start learning, you must first master the basics of HTML, because it is the language with which you will build the skeleton of the page and determine where each element should be located.
Once you have mastered this, it is time for CSS, that is, giving the elements, shape, color or size to the look. It is thanks to this language that the site is becoming more visually appealing.
This order is very important. Departing from it can have a huge impact on your skills and further development of knowledge.