What is the definition of gross domestic product (GDP)?

I want help to solve following questions accurately:

Is GDP a good indicator of a country's wealth? Why or why not? Explain.

Explain the four main components of GDP (i.e., C+I+G+(X-M)).

What is the difference between nominal and real GDP?

What is the consumer price index (CPI)?

Demonstrate how to use the CPI ( CPI given) to compare dollar figures from different times (for example compare the cost of a cup of coffee in 2004 to 2014).

Why is the CPI important to seniors on a pension?Why would the CPI be important when you are negotiating your salary for a new job?

What are the top 10 GDP/capita countries in the world? Please find the latest numbers. How does Canada and the USA rank in terms of GDP/capita?