Answer:
La langue française (because the word "language" is feminine).
Française is the feminine form, and if you're describing a masculine noun, the adjective would be français, without the "e". If you simply want to say "I speak French", you would say "Je parle français".
If you are a male, "I am French" would be "Je suis français". For a female, "Je suis française". (Notice that in French, adjectives referring to nationality are NOT capitalized as they are in English).