[Question] Can i give a key to a friend or do i need to activate it on my account?

You must activate it on your own account.

https://www.steamgifts.com/about/faq

This is a good place to start :D

If I win a game, can I regift, trade, sell, or remove it from my Steam account?
According to our guidelines, no, all games you win must remain activated and redeemed on the Steam account you used during registration. Failure to activate games you have received will result in a suspension.

From FAQ which I'm surprised you didn't find while looking for answers

If I win a game, can I regift, trade, sell, or remove it from my Steam account?
According to our guidelines, no, all games you win must remain activated and redeemed on the Steam account you used during registration. Failure to activate games you have received will result in a suspension.

Won games have to activate on your account, otherwise you will be suspended.

Check the FAQ

If I win a game, can I regift, trade, sell, or remove it from my Steam account?
According to our guidelines, no, all games you win must remain activated and redeemed on the Steam account you used during registration. Failure to activate games you have received will result in a suspension.

Thank you all for your answers! Sorry i didn't see the FAQ xD

Seeing as you are quite new here, welcome to SG.

If you haven't already, please read the ToS, FAQ and Guidelines of this site to avoid rookie mistakes.

A few interesting links for new user:
https://www.steamgifts.com/discussions/announcements
https://www.steamgifts.com/discussion/XaCbA/list-of-all-cv-levels-and-their-corresponding-real-cv
https://www.steamgifts.com/discussion/GeDfy/failure-to-activate-and-regifting
https://www.steamgifts.com/discussion/z5iPh/psa-make-sure-the-game-you-receive-is-the-one-promised-to-you
Comment formatting

And, maybe in a bit of time... Unlucky-7

you can give it to someone else and in return for your generosity the SG mods will gift you a ban on here until you get and activate a copy of your win