Steam > Steamapps > Common > Counter-Strike Global Offensive > CSGO > CFG>autoexec.cfg (This CFG will set your game to optimize bullet registration, net you higher FPS, and remove most of the unneeded graphics settings.)

Right click Steam icon > Library > Right Click on CS:GO in library > Properties > Set Launch Options > Type:

“-console -novid -freq 120 +exec autoexec.cfg -high”

Change '-freq 120' the number to either; 60/75/120 depending on which HZ is your monitor.

In the box. It makes the console open upon launch, disables the video upon launch, sets your refresh/hz to 120, executes the autoexec.cfg and sets CSGO to high priority.