Looking for Rates up

http://fate-go.cirnopedia.org/summon.php
That's the link where you could find and predict banners, but remember we're two weeks earlier than the Japan schedule for banners so keep that in mind.

But to your question sadly we don't have a rate up for Atlanta, but you could try on the story gacha if you want, but who even tries the story gacha?
For karna you could try the lucky bag summons for guaranteed more specifically the each class lucky bag summon, but it doesn't assure you will have karna other than that the each class summons for lancers