Perform deathmatch - Deathmatch is a game mode where there's no CSGO Skins objectives, no rounds, and no fretting about cash. It is the purest distillation of CS's gunplay, and because there is no downtime once you die like there's in a real match, it's the quickest way to learn just how all of the different guns do the job. It won't teach you team strategies or how to play objectives, so you ought to play with other game modes also, but it's certainly a fantastic way to start learning the recoil patterns and other behaviors of the game's various firearms.
Play target maps - This training procedure is a bit old-school, and you don't see as many people doing it, but I still find it a really helpful way to practice your own rifle aim. Aim maps are maps built specifically in a way that compels you to get precise aim; for instance, a number of them are going to have walls that go up to the neck of those opposing players, forcing to take their heads. Since rifle headshots are such a potent tool in CS matches, this is a fantastic thing to learn ancient and practice often.
Watch pro flows - There's several professional CS:GO gamers that regularly stream their training matches on Twitch. You can learn a lot from simply watching how they play, how they communicate with their staff, etc.. Not everybody does this, and some people will argue that you'd be better off spending this time only playing the game more, but I know that it's helped me out a great deal. A healthy mixture of playing and watching has done wonders for my CS game. Here's a handy list of CS:GO pros who flow - check a few out and find somebody who you like watching.
A couple of times annually, there is also major CS:GO tournaments, that CSGO Skins for sale can be extra helpful to watch as a new participant, as the games are generally commentated by those that are extremely knowledgeable about the finer points of CS strategy.