Need Help on few points

Hi, I was practicing one of the excel sample sheets,

Sample data

Kindly help on below points to find out the solution

1.) Show Sales by Customers and Product Line with Percentage Change.

2.) Calculate the Order v/s Sales ratio.

3.)  Show the % of increase/decrease for Orders V/s Actual Sales by Year/Month.

4.) Customers whose sales are constantly dipping.

5.) The trend for Customer-Sales using Transaction Date with filter for top N Customers by Sales.