I am not really sure about the first part, because the verb 'to do' (하다) is missing, but I think it means : No matter what you do, we can't see the same stars.
당신이- you (이 makes it a subject)
상관없이 - no matter what
우리는- we (는 makes it the subject)
별을- stars (을 makes it the object)
볼 - see
수 없다 - can not
Please correct me if this is wrong ^^ (I am a beginner as well)