I actually speak very little Korean, despite being part Korean. I know how to text in it and say some words like, Hello (formal;informal), yes, no, bye (formal;informal), f*ck (Even though they don't really curse much), Thank you (formal;informal), mother, father, big brother (male;female), youngest, cute, and a few more!!!
Now, texting in Korean is a bit harder because on the computer, M would be were A is on the English keyboard, and so forth. Very, very confusing. If you know the Korean Alphabets then you should be ok on spelling words.
Here's some words:
오빠= Big brother (for females)
I learned Korean from YouTube , teachers, and simply just watching Korean Dramas. If you memorize a word in Korean and keep saying it, you'll get better. Start off small, like words then work up to phrases!