Nice pile there! I'm guessing this Composting Day is a (US) national thing? A quick search shows 'Learn About Composting Day', is that the one?
Please tell us more. Over here (Netherlands) we do have a 'national compost day' in March, where you can go and get compost from the municipality. Great initiative, though the quality of compost is questionable as it's the end product of whatever the municipality collected in the green bins over the year. And people put in, well, everything. So, it is definitely not a 'Learn About' day, while we could use that for sure over here in my experience.
Good luck and enjoy presenting! If you are willing and allowed to, could you share your full slidedeck afterwards? Or at the odd chance of it being recorded, please share the video!
Really cool that you are doing this for your local community =)