Learn how to say "How are you doing?" and other useful phrases in lesson 54 of the Beginner Korean Course.
Remember that all of the lessons in this series go in order (starting with the alphabet), and there will be a total of 100 episodes once it's all uploaded.
You can start learning Korean from the very beginning with this course, and finish this course with a decent introductory knowledge of the Korean language.
I'll keep uploading two episodes every week until it's completed.