The difference between beach water safety and lake water safety is that they tide and water current is stronger at the beach than the lake, which can make you drift in the water which is very dangerous.
Waterborne illnesses is a virus or sickness that needs water to be transferred to someone, or to make someone sick. You prevent from getting them by being careful where you swim, take showers, and make sure not to swim with open sores or wounds.
You make sure you don't dive in shallow waters, you don't flip off the side of edges, and if it has chlorine in it, make sure you let it sit before getting in. All of these will make sure you don't get hurt at your pool.
If an infant is in the water, make sure that they have a flotation device on them, they are always parent or adult supervised, and in safe and calm water conditions.