I'm trying to figure out how I can give out referrals. I know about my private referral link. So what do I do with it? Can I like just copy and paste it onto my Facebook page?

You can put it on your Facebook page, yes to advertise the game and to get more players to join Battledawn.

You can put it anywhere really, not on the forum boards here though (I think), other forums if it's not breaking their rule of advertising, and even through instant messengers.

you can get the link and give it to people, therefore spreading the name of Battle Dawn