I have compiled a list of sources for the elements that are available to the amateur chemist. Chlorine will be discussed here.
Chlorine is a light yellow-green gas. It is the second halogen. It is less oxidizing than fluorine but more oxidizing than bromine. It has a choking odor and was used as a poison gas in early World War I. Chlorine is used for bleaching and disinfecting. It dissolves in sodium hydroxide to make bleach solution. Removing the sodium hydroxide by reaction with acid produces chlorine gas again. Chlorides are more benign. Sodium chloride is one of the most common salts.
In element form: Electrolysis of sodium chloride solution with a carbon anode makes chlorine. Hydrochloric acid and manganese dioxide produce chlorine. Hydrochloric acid and bleach also produce chlorine.
In compound form: Bleach and salt contain chlorine. Chloride is a common anion.
Here is some chlorine gas I temporarily produced from hydrochloric acid and bleach reaction. I did not retain it.