I have been using Stack Overflow for a month now. There are "yes" and "no" options for positive and negative response, respectively. I was wondering, how does this feedback affect my reputation?
You don't get any reputation off of those whatsoever. These feedback options are only gathered for statistical purposes as far as I know. And as of yet I don't think that there are any set plans for what to do with the data gathered (or at least I'm unaware of any).
What you could use it for however is to gather some insights into how useful you have been yourself to unregistered users of the site via this data explorer query. It might help you in improving your own contributions and gathering more upvotes in the process.