In this section of the Complete CSS Tutorial For Beginners, We will talk about CSS selectors. But firstly, you need to know about the CSS syntax

CSS selector selects the HTML tag/element that you want to apply styles to.

We can divide CSS selectors into five types:

Simple selectors (select elements based on name, id, or class)
Combinator selectors (select elements based on a specific relationship between them)
Pseudo-class selectors (select elements based on a certain state)
Pseudo-elements selectors (selects a part of an element)
Attribute selectors (select elements based on an attribute or its value)
This page will explain the most basic CSS selectors (simple selectors)
https://devwithmike.com/tutorials/complete-css-tutorial-for-beginners-css-selectors/