Newbie here, need help for build progression.

Hi, I've recently started playing SOTFS. I started as Knight and beaten The Last giant and Pursuer.

I want Ivory king GS as my main but that is far into the endgame. Can anyone kindly suggest what weapons/build should I use until I get it? What should be my primary focus in stat investments?

Also what would be the quickest way to get it before the final boss?