Hi do i need to download every patch or i just can install the new one?
And if im in game i still can download these patches in the background?

You need to explain more about your setup and what version of the game you are playing. Details are everything. You can download them, but you absolutely cannot install them while playing the game.

Well at this moment after i click "PLAY" in Witcher 3 is not opening.
I click play and nothing happens

THAT is what you call details?

I didn't give you details of that because i have other problem now with clicking PLAY.

I bought W3
I installed W3
Now i'm downloading patches on gog to W3

Do i need to wait till every patches will download or i can play now?
I guess i have to wait because next to The Witcher 3 is showed patch 1.12.1 which will be installed after i install before
Maybe it will fix my problem

I already told you: you CANNOT play the game while patches are installing. You MUST quit the game and wait for the patches to install. This goes for any software, not just for games, and not just for The Witcher 3.

I have a new Installation but this is what I was told and it worked.

you need patch 1.01 - mine just downloaded on its own when I opened the game (clicking on the game shortcut NOT a GOG.com shortcut) and had an internet connection active - you should see a small window called GOG Galaxy

After that I went to gog.com and downloaded patch 1.10 - all four parts
and 1.12
I got off the internet and installed them...

things were working just fine until I tried to launch the game just now with an internet connection
- then I got all kinds of weird error messages and no galaxy window...
when I disconnected from the net and again clicked the witcher shortcut - the galaxy box popped up

I mention this because you said you couldn't open the game - did you have an internet connection at the time?

good luck - I was a bit confused myself with the patches