Fill 2 glasses with ice. Pour 6 ounces lemonade into each glass. Divide the Coca-Cola evenly among both glasses and garnish with lemon wedges.
Lemonade: Fresh is best (I'll walk you through how to make homemade lemonade), but you can absolutely substitute store-bought lemonade from the bottle or carton. Or start with 12 ounces of frozen lemonade concentrate made according to package instructions.