As someone who taught Intro to Speech for 30+ years, I will offer the following. Big Mikey has the right of it for possible topics. I personally would advise you to stick to the difference between a kilt and a pleated skirt.

Whenever a new wannabe want's a kilt, the sticker shock is very real. However when they realise the complexity and labour involved, then they begin to realize that the prices are not at all out of line.

But this is your speech, just remember the general rule, tell 'm what you are going to say, say it, then tell 'em what you said.

Good luck!

"bow"