The p-value of a two-tailed z-test for a population mean is 0.064 when the level of significance is 0.05. Which of the following statements are true?

II. The mean in the null hypothesis is true.

- I. A one-sided test using the same data would indicate a statistically significant result.

- III. The test has failed to prove that the alternative hypothesis is true

I and III are correct but I have couple questions.

1) When dealing with two sided tests, significance levels(alpha) are halfed just like P-values

2)What does it really mean by "statistically significant result" ? I tried googling but couldn't find a good answer.

Thanks for your help in advance.