On the right site of diamond city is a house and I found some mysterious crayon suns they look more like tv's with sun rays, have they been discovered yet? And if yes what are those? I just can't find anything about these things

I would post screenshots but I dunno how on that site ^^

And what looks like chalk drawings on the floor of the prydwen. With toys nearby.

Odd.

I mean why does no one care about it it's freakin mysterious ^^

There are signs that a certain faction uses that involve symbols (arrows, squares, dots) surrounded by sun rays, drawn in white chalk.

As for the house, talk to the Mayor's secretary to buy it for 2000 caps.

I have found a few of these. The first was at "Bedford Station" where you get "The Dutchman" quest. They seem to indicate that something decent is hidden close by. You usually get a caps stash and something else (either ammo or medsor weapons). I have found anything from stimpacks to mini-nukes.

They are signs for a specific in game organization. Follow the Freedom Trail to find out more.