Easily one of the greatest FPS in the history of video games, and I absolutely love this game. CS is easy to learn but hard to master. Once you get into it and learn the basics, you can't stop playing it. This game is a masterpiece.
The skill-based matchmaking system isn’t perfect, but it does work, and it pairs you with players with similar skill levels to yourself. While in the lower Silver-ranks you will still meet the inevitable trolls, cheaters and the occasional smurf, you’ll usually end up in a game with people that are of similar skill to you.
If you're just getting into the game, I'd highly recommend you to buy prime because non-prime is now unplayable, it's filled with cheaters and smurfs who will just ruin your experience. Now that the game is free, cheaters get banned and it literally takes them two minutes to create a new account.
In the game, you'll come across all types of people. Some will be friendly and some will be toxic. Once you get good, you'll eventually be called a cheater because every CS player gets called a cheater at some point. People may report you, but just take it as a compliment.

Greatest FPS game in my opinion. You don't need a powerful rig for this game, an average one will do just fine. 10/10 Highly Recommended. Just know that this game is full of cheaters, especially non-prime. There are cheaters in prime but quite low in comparison with non-prime.