Do tampons hurt?????( I know this is a disguisting question)?

Im sorry for this weird question but do tampons hurt for the first time? I have to use one because my friend is having a party at a water park tomorrow and ofcourse I have to have my period two days before it, so I have to use on for the first time, or else I cant go.. I really want to go, so I have to use it, but im SO scared. Once I had to have something go up my butt and it was so painful so I dont know how this is gunna turn out.:( Im only twelve and im really scared please try and comfort me some how so I calm down because im really freaked out right now...:(