It truly sounds like you are way too new to train anybody. Is it fellow divers that are wanting this or brass that don’t dive? If it’s the brass, your team lead should be speaking up.
If you’re forced into it, start with: Who is your audience? Then, what are their needs? I’m making an assumption that you’re expected to train fellow LE divers. I might throw this on it’s side and say the most appropriate training a new diver can give a seasoned one may be a basic refresher. Something basic like underwater navigation, but make it more challenging than just a square. Have them each plant colored flags along their path and then video the path and see how close or far apart they all are. Make sure they are accompanied to ensure they’re constantly looking at compass/computer, not looking around. Maybe even put some “landmarks” nearish the navigation plots to try to throw off those that look around.
Whatever you choose, remember that the true test of your knowledge is whether you can teach it to someone else. So stick to what you know best. But also try to make it a basic skill that they rarely use. I’d assume they often use search and recovery skills.