Waited for this.
First every champion requires mechanical setup to just get to know them,no matter the elo.
Secondly,Irelia is no where mechanically "difficult" consider her kit has two point and clicks,a simple active,and 4 "skillshots" which are as fast as an ezreal mystic shot,while she's either point blank in your self/running away so there's no way to miss.
The only small brain cells Irelia needs is when to active her Q for the reset or fast farm/gap closer.
W-are you in combat with champions?press w
E are you in combat with champions? Losing more ho while fighting/running? Point and click/turn back and point and click-free stun
Chasing champions?press E.
Waveclear and sustain/ damage and sustain? Up to you to decide,press R.
Also every melee main must have simple and advanced team fighting tactics with specifically for their champion or just the basic.
Last one,every champion always has room to improve in the game,except few completely braindead idiotic champs which are a shame to the game like Garen,Sona and Warwick