Nicht is generally used with a verb, while kein is used with a noun. Eg, Ich renne nicht = I do not run. You can't say 'ich kein/e renne', it doesnt make sense at all! It doesn't sound correct either. :) Ich habe keine Idee = I have no idea. Sometimes of course, you can both nicht or alternatively, kein. Eg, ich mag Äpfel nicht or ich mag keine Äpfel. It means the same. Just remember that when it comes to verbs, we use nicht and when we need to negate a noun, we use kein(e). :)
You're welcome. I'm not a native English speaker but I have a Bachelor's degree in English Language and Literature and articles were always a pain in the neck for me so I made sure I learned them. Thanks for the French piece of information. I kinda gathered other languages are more flexible regarding articles and some don't have them at all (like my native language for example) but in English any countable noun simply needs an article.