I sort of find that Lang-8 is good once you have some knowledge of Korean... I'm sort of struggling with it right now, as people keep saying things to me and I don't understand them!!!
Alexis that is a totally understandable problem to have. Take heart in knowing that even people like holdfast (emily) and austin have to stop to translate some of the things that people write. It's natural language and it's solid gold - once you figure out what's being said
For me, I setup a study website full of my own personal writings, phrases, vocabulary words, and other common (and not-so-common) things that I run into in Korean. Once I run into something that I don't know (which is daily, mind you) be it an insult, a compliment, or just a thought, it gets copied and pasted for me to study later. Then, if I can't figure it out later on my own (or if I want to get someone to check it to make sure) I meet with my roommate, tutor, or just a friend to have them check it.
Pretty soon, you start to run into stuff that you already have seen a bunch of times before. Then these common things turn into topics. Then, so long as the conversation stays on the topic (at the restaurant, at school, personal hobbies, etc) then you find yourself with someone unique and personal that you can talk and write about.
Hey, you gotta start somewhere, right?