What are the best ways to learn how to start playing CS:GO?

Practice. Practice. Practice: You won't become a better player until you start paying maximum attention to this game. Watch Streamers and Popular Pro Players Play: At least on Twitch, you'll find plenty of professional CS:GO players streaming their games with other players on a regular basis. Find out how they play, how they communicate with their team, or when they face difficult situations on the map.

Watch CS:GO tournaments and events around the world. From this article https://readallnews.home.blog/2023/01/24/how-to-improve-your-skills-in-cs-go/ you can also learn a lot of useful things from cyber sports and cs:go in particular. Find out how professional players behave in the game and try to replicate it when you play on your own.