You have to learn about eco rounds & stuff. Don't watch a video but if you don't know proper smokes and flashes it's hard to rank up. Just pull your mouse down slightly when spraying with AK47(down then slightly right after 8-10 bullets). Don't spray at long ranges(only do so in short ranges).
Always go for HSs with Ak47 at long range(it is 1 tap kill) which really helps. You might want to adjust your crosshair too as the default one is just dreadful(check this map that lets you do so: Steam Workshop :: crashz' Crosshair Generator v2 )
CSGO expects you get rifles/etc in "Buy" rounds i.e when you money is stable(rifle + armor + defuse kit when CT and maybe a pistol like p250). Shotguns are better in eco rounds(they give 900$ kill bonus instead of 300$. Shottys can be used in buy rounds as well but as they're not effective at long range people donot buy) or one can really effectively use them in short ranges(like banana in Inferno).
The spray is to add realism. Because real world guns also recoil a lot. And a gun is never 100% accurate(esp rifles). Even the AWP in CSGO has a 98% accuracy(according to people who have analyzed ingame files).
I have played 500 hrs and have barely reached Silver 4(very scrubby rank). Internet trouble has played a big role too as I often DC between matches(and unlike dota2 we cannot pause here and even the loss of a single packet is difference of life & death).
Thing is those who like running & gunning won't ever like CSGO. You make elaborate strats, fake sites, YOLO rush & what not in the 30 rounds of compe. The rush we get when we clutch 1v3 or something similar is what that keeps everyone going(among other things).
And I never watch a goddamn video to learn a game, I'll play and learn and I'll die 1000 times but won't watch videos. Don't really have time to watch video instead of playing the game
Everyone has a different opinion on this. But learning smokes and flashes(and some other things) have definitely helped A LOT in this game. You can't just learn some of the smokes applied without actually watching them once (in a pro match or a YT video).