Welcome Mattia,

If you're dressing for a wedding you'll need a kilt, sporran, hose, flashes, and most likely jacket and possibly waistcoat, and sure why not a sgian dhub?

You might want to check out these helpful free resources for information about kilt wearing and tartans: Kilts and Tartans Made Easy by Dr. Nick Fiddes, and the articles by kilts and tartan historian Matt Newsome available here. Both gentlemen are members of this forum as well.

Best regards,

Jake

PS. Don't forget that the search feature is your friend.