I need to select this animation only if i’m pressing Q key. What boolean thing should I connect?
In Idle/Run state remove that blend and leave only your thirdperson_idlerun.
Create a new STATE (eg.: “Q Pressed”) in your state machine and set the transition condition that a new boolean (eg.: isQPressed) is true.
Inside that state put the animation you want when Q is pressed (eg: your Readiedblend).
Add a transition back to “idle/run” for when your boolean is false.
Now in your character blueprint add a boolean (eg.: QActive) as well and toggle it when you press Q key.
Finally in your animation tick, update the boolean (isQPressed) with the character boolean (QActive)
That should work, sorry I’m not great at explaining things.
Thanks for quick response, but i’m actually a noob, so where is this animation tick? Is it event blueprint update animation?
In that case, how do I solve this:
I’m also new, still in the progress of learning 
That is the animation tick yes.
Assuming you have the “controlling” boolean in your character, you want to use the node “GetOwningPawn” and then cast it to your character type, probably “3rdPersonCharacter” if you are following the 3rd person template, and from it GET your boolean “QActive” and set it in “isQPressed”.
OMG, that worked. Thanks a lot
Glad I could help!