Counter-Strike Global Offensive, a game I can recommend to anyone willing to spend 15$ to unlock Prime status and with it comes Prime Matchmaking, something you want to have if you dont want to play aganist Cheaters only because Counter-Strike Global Offensive is now for free.
The gameplay is very tactical, but to get the full tactical experience, it would be best to create a fullteam : a team of Members you know, for example your friends. You really want to play in a full team first because if you dont, the random people you meet, probably will do their own thing. Communication and teamplay is essential to winning in Competitive, both can become quite the challenge when playing with unknown people who you have just met.

The game itself is wonderful, but I would not recommend for any beginner to play alone for the above mentioned reasons. Most beginners would have NO FUN if for example you get qued up with 4 unexpectedly talkative Russians who with best microphone quality start the smal talk.(ironie) Little Spoiler alert:
Said russians will have such bad microphones, that your ears will bleed because, it sounds like their voices where recorded by a toaster, bought on a scamming-site.

Anyway, if you happen to know 4 people who you can play with, Nice!
If not, well, in advance, my apologies, RIP "your ears". (Please take everything I just wrote with humor ;) )