There's all sorts of dares on getDare, though sometimes you have to dig into the past a decent amount to find one that fits you. Also, I wouldn't become obsessed with following the exact letter of a dare as written if it doesn't work for you - decided what you're going to try, commit to it, and then do it! I especially like the dice dares for a good balance of knowing up front what you might have to do, and the surprise of rolling the dice and having to do something.
You could always start a "give me dares" thread with an explanation of what you're looking for to get dares that work for you. Or find a good master/mistress who will work with you to push you without going too far (though of course, finding a "good" master can be hard). Plus, having the dare given directly to you might be the push you need to actually try it!
As far as public dares go, I'd say start with "hidden" dares, or dares that are slightly embarrassing but nothing like going nude in public that could legit get you in trouble. Personally, I've been walking barefoot in public a decent amount, which can get weird looks but isn't really too crazy. So I'll end by daring you to go for a walk somewhere barefoot
