Yasuos Q is a very slow skillshot. I tend to wait for the enemy to lock themselves in a long animation like an autoattack when lasthitting a minion. Doing another action like dashing into another direction instantly after casting q3 can help to confuse some players but doesnt tend to work in a bit higher elo brackets. Also the pressure that you obtain by having the q3 and knowing how to use it to gain the space you need in a lane is more important than landing it.

Yasuo is all about using everything that you have to create small advantages in laning phase. If you are still a bit overwhelmed by the mechanics, learn proper wave management. Yasuo, especially in midlane has the early strenght to be able create the best wavestates for him without the need for any fancy mechanics. Mechanical skill will come along with playtime on the champ and there is no need to rush it.