Literally, this says "I say you what"? Generally, "我说" is simply an introduction to a quote you said or just a filler introduction (it's like saying "I say" at the beginning of each English sentence; it's not needed, but some people simply speak that way).
"你怎么“ can't really stand by itself. It needs something else to have some meaning. For instance:
”你怎么了？“ is an expression used to show concern for the other person (the equivalent of "What's the matter?" or "Are you okay?" in English).
"你怎么样？” means "How are you?"
I hope this helps answer your question. If not, please let me know.