I'm improving little by little, but overall I'm still shit as at GO. I found some custom maps on the workshop which I find are helping me with my reaction time and aiming etc which is pretty cool though. Also, downloading the crosshair generator map was super useful too. Would recommend.
Just play casual match making. Also play Arms Race to help with your aim. Instant respawns can make weapon practice less frustrating.
Played a couple of games last night and got fucked over by ending up on a group of derankers twice who subsequently kicked me so copped a derank in the end.