Use aim_botz for shooting practice, I recommend training head cadence with 1 hit. Over time, your speed will increase and you will soon have a higher aim level. Currently, Global Elite in Brazil.
Aimlab. It's on steam and free, overall the best aim trainer i've ever used. I have about 10 hours into it, which isn't alot for a aim trainer but its really nice. Community workship aswell so you can use other peoples trainings and gun models, etc.