Pre Race Prep
Warm up for 10', make sure your bike is shifting properly and nothing is loose or rattling. Check tire pressure and make sure handlebars, stem, skewers are all tight. After wu, do 4x20" fast with a full recovery between each.
Open Water swim, start easy, practicing heads up navigation, and after a warm up, swim race tempo on/off as needed, but don't overdo it. Try to use navigation of "heads up" swimming to site your landmark on the horizon during sprints to swim a clean, straight line.