How do you make homemade carbon dioxide?

Vingar and Baking Soda.

Ethanoic (Acetic) Acid & Sodium hydrogen (bi)carbonate.

The efferevescence seen is the release of carbon dioxide.

Another method of making homemade carbon dioxide, although not thought as such, is a motor car/autombile engine. The exhaust gas is carbon dioxide. Every house has a motor car.