How do people get used to A attack

i dont use it, i dont see it useful tbh

I never could get used to attack-move-click on A. I found it resulted in having to take my fingers away from my ability keys and it was awkward to use.

Fortunately, my mouse has two extra buttons on it (Back and Forward), so I just rebound it to them.

Practice.

I've been doing it for years :P SC1 and Dota 2 days so.. ive been doing it for 10 years lol.

I use it to orb walk or when facechecking bushes that ive chased someone into. That way there is no misclicked.

Try setting to to smart cast, its a lot more smooth that way.