This is the output after I run the regression analysis. I have 3 questions about it. 1) what does the p-value mean in this case? 2) I hear that if the p-value > 0.05, the null hypothesis will be confirmed. So can I still believe in my result as y=-457+0.42x ? - please explain this. 3)what does the "lower 95%" and "upper 95%" mean (in the right of the table)? - please explain by graph?

Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Intercept -457,771827 54,99689373 -8,323594224 4,47162E-06 -578,8191739 -336,72448 X Variable 1 0,423263123 0,043492996 9,731753561 9,69453E-07 0,327535684 0,518990563