l've got two left feet! 
→ 나 몸치야!
 [예문]
A : l tried taking salsa lessions, but l'm no good. l've got two left feet!
    살사 레슨을 받아 보려 했는데 잘 못하겠어. 나 몸치야!

B : Maybe dancing isn't such a good hobby for you after all.
    춤추는 건 너한테 맞는 취미가 아닌가 봐.

A : Definitely not. The instructor said l was the worst student
     she's ever seen!
    진짜 그래. 선생님이 나처럼 못하는 학생은 처음이래.

※유사표현
- l have no sense of rhythm.
   난 리듬감이 없어.