What does high R-squared value mean. I got .9999 as R-squared

What does low P value mean? I got <0.0001as p-value

Can You have high R-squared value, but low p-value

what does R-squared and P-value indicate

How well does the linear model describe your data when you have high R-squared and low p value

Are there problems with the data when you have high R-squared or low p value. Explain