Play some OSU! that helped me a lot when i started learning how to play pc the more you play the better your muscle memory gets

If you want to get good at FPS games, do what i do.

If the game has bots with a difficulty setting, start on the easiest and work your way up! its how I got good at CS:GO... well... sorta.... ( Nova Shotgun Skrub )

If u dont have a gaming mouse and keyboard / mouse pad i highly recommend getting those if u actually want to play like a boss and destroy everyone In csgo i got REALLY good just by learning the recoil of the ak 47 and learned to aim with a pretty slow sensitivity. U want to set up ur sensitivity in a game and shoot a head sized circle in a wall with a pistol then look at the circle from a little bit away then move left and right rapidly and try to keep ur crosshair on the circle. If u cant get it to stay lower ur sensitivity till u can keep it better. Hope i helped

Knowing the controls and your way around keyboard and mouse will help... tremendously. But that will just come overtime for it to feel more comfortable and natural. As for increasing your skill on CS:GO, there are many things, but the best is by playing the game. Just continue to play the game and have fun, you will get better as time goes on. CS:GO isn't a game you can master in little time, it will take months upon months for you to get even "good." Whenever you want to practice and warmup, hop into a deathmatch. Since you just started I would suggest a regular deathmatch server, casual. Here in the future you will want to go to custom FFA Deathmatch servers. The players there are much better and there are more targets, so you will get better quicker. Or warm up faster.

Find the best Mouse DPI for you personally. some people like it hi and some like it low.