I often confuse myself choosing words among of 'no', 'not', "don't".
For example:
You don't say => You not to say => you no say (?not sure)
don't need your money => your money is not needed => No need your money
Not required => don't required => no ?
From the examples of confusion sentences above, can anyone show me the actual mistake here and share your tips on how these words should be used properly.
I think you must be asking which examples are complete sentences, because most of the examples you've provided are not. The most basic complete sentence must contain a main clause, which has both a subject and verb, and the sentence must express a complete thought. There are other requirements you can read about here: http://www.chompchomp.com/terms/completesentence.htm
You don't say => You not to say => you no say (?not sure)
You don't say is the only sentence that is complete. The subject is you and the verb is do. The other two examples are ungrammatical and incomplete. Both You not to say and You no say are lacking the verb do. In these two example, to say is not the verb. Instead, it is what is called a bare infinitive, meant to be preceded by the verb do. You can learn more about do + bare infinitive here: http://www.grammaring.com/do-does-did-bare-infinitive.
don't need your money => your money is not needed => No need your money
Of these, only Your money is not needed is a complete sentence. Don't need your money and No need your money are both missing a subject (such as "I" or "we").
Not required => don't required => no ?
None of these are actually sentences. Not required is a phrase, but it's neither a subject nor a verb. Don't required is ungrammatical, because the do + bare infinitive construction says that you should use the bare infinitive require, not required. If you're trying to make a complete sentence, you can say: This is not required.
