Click on your name in the top right corner, choose Account Settings, on the right side of that page choose Notification Settings, then find where it says "Someone gives reputation to something I posted" and turn that off.
Do people still wonder about the rep stuff? I've been keeping a spreadsheet for the last few years and could update it in the Lounge if people are interested.
With the major board upgrade last year, you can do different types of reactions. The built-in ones are something like upvote (+1), funny (also +1), confused/question (no rep point) and downvote (-1). We can add others if we want. We currently only have the upvote enabled.