It will be A LOT like any wedding you've been to before and no one will object to your Kilt wearing.
Ask those who invited you if they would like you to wear a Kippah. (If the wedding is taking place in the Synagogue they usually will. Or they will tell you what type of headgear they would like you to wear.)

Since you're there as a guest you won't have to take part in the ceremony at all, but if they want you to take part in any of the after party traditions they will usually explain these things to all of the non-Jewish guests.


Just have fun. Jewish weddings are great and I can honestly say I have never been to one where there wasn't at least one Kiltie present other than myself.


Good luck!