how to download betas on steam

[koppins851]

hey there,

I just bought myself a gaming laptop to play this game, first thing went to steam and bought the game.
now it wont download the beta versions.

steam wants a code to join the betas- where do I find the codes?

yes I tried searching here. but no one seams to have the same problems.
steam showed an update but I cant find what version is running.
of course I want the newest beta, than upload all the mods.

maybe you guys can help a steam virgin.