I soon found out that naked mean not in garb, or period clothing. I was sure they were not talking about have no clothing on, but I wasn't sure just what they meant. Before you pick a persona, it is difficult to decide what clothing to wear for an event, so basic is best. For men, a simple tunic with a pair of pants, and for ladies, a skirt, and simple shirt will do, or a long tunic.
Tunics are simple to make, and take little time or talent.
Even non sewers can tackle a tunic. There are some patterns available commercially, and are decent as starters. They are not terribly authentic, but will do. I have seen some wonderful outfits made from these patterns, and some that looked, well, to be nice, interesting. So, until you have pinned down your persona, stay basic.