How do I get be mine 8 bundle on Steam???

WOAH!

No idea with Groupee bundles but most of them are either 1 key for all the games or a page will all the keys. You have to wait til the creator of the giveaways sends you them.

Click(here on SG) Giveaways -> View Won. I think there should be a link or key or something there. I'm not quite sure how the Groupees mass giveaway works.

they could be desura keys since all the keys in that bundle aren't for steam

Some games are for desura, not for steam, make sure you're using the right ones.