What are some good steam groups/discord servers/websites that have good giveaways?

https://www.steamgifts.com/ probably.

Many private groups here will have some requirements associated with your SteamGifts statistics, once you level up a bit you can try to browse some of those. They often come with additional rules for joining as well. I can recommend TalePlay that I joined recently, super friendly place with reasonable people.

As a newer member it would seem like you may qualify for Unlucky7 which is a nice group for starters.

I'd recommend discord.gg/peekyboo, pretty nice community, and I've won a few games from there