frustration is killing me !

Ok guys clearly i am stupid and i apologise for the scale of my ineptitude but i simply cannot get my head around the flow of information and basics of the blueprint system
for example i am currently trying to set up a system in which the left ctrl key causes my third person character to crouch. i have set up the ctrl key in project settings and i have a crouch animation waiting to be implemented but… well i cannot figure out which way the information runs from animation blueprint to character blueprint or the opposite .

i followed the third person with blueprints guide https://www.youtube.com/watch?v=hRO82u1phyw but i felt i was simply copying the guy i have watched a million and one tutorials but i simply cannot see the relationship between the animation blueprint and the character blueprint … even tho it should be obvious by now it simply is not …

every time i think i have it figured out i try to use a node in one of the blueprints only to find it is not available in that blueprint i am very confused and when i watch tutorials it just confuses me further i am not an intelligent guy but i am not as dumb as this is making me feel …

i have a working third person game with models and animations but if you asked me how it works i have no idea…

i dont even know what i want you guys to do to help me im kinda stuck at the moment and cannot see a way forward i dont even know what to ask as there a more than enough tutorials online that explain everything i want to know but when they jump from 1 blueprint to the next 30 times a minute im left thinking why ?

Casting is the magic world. The animator blueprint “Cast” the player and can look the values in player.

https://forums.unrealengine.com/showthread.php?43758-Help-with-assigning-an-Input-Action-to-a-variable