Period. It comes at the end of your sentence.
Commas show it is time to breathe, and pause while you are reading. Commas guide the reader how to express the words in phrases, giving more detail.
Colons are a symbol that comes before a list: things, ideas, ingredients, etc.
Semi Colon; further details or explains the previous word or idea.
Sentences must have a subject and predicate (including verb) to be complete.