What am i missing in my blueprint ?

Hey there,
i started today just for fun trying out blueprints (i will use C++ as language and i will never use blueprints but today i said my self lets try it just for fun and see what it can).

Well, i made a box inside of my light blueprint as trigger, my goal was to get the light off when the player is near the light and get it back on when the player is far away.

Now watch my Screenshot, my first result was this::

But that didn’t worked.

My next result was that:

And THIS worked perfect.

So my question is, why did the first result (first screen) not worked ? (i guess because something was missing ? right ?)

In my second picture it works fine. Is that the right way that i choosed in my second pic ? or is that “actually” also wrong ? cuz everything works fine now.

I ask this to learn from blueprints a bit. And i have already a idea why my result in the first pic didn’t worked, because:
Once i walked inside the trigger (box), the box sends the “command” SET BRIGHTNESS but nothing receives that SET BRIGHTNESS. Because of that i have to use at the end of Set brightness SET intensity to RECEIVE the “function” right ?
I guess i understood everything right already but i am not sure haha