An example of a household endothermic reaction is boiling water. The process of water going from the liquid to gas phase is an endothermic process (you have to put heat into the water).
An example of a household exothermic reaction is the burning of natural gas occurring on a stove-top or in an oven to cook food. The natural gas, mostly methane, CH4, burns by combining with oxygen to from carbon dioxide and water (and some other by-products such as carbon monoxide). This exothermic reaction creates the heat to cook with. Another example is burning wood or coal.
An example of a substance in the liquid phase is water! Some other common examples of liquids are oil, gasoline, rubbing alcohol, and acetone (nail polish remover).