A number of students have emailed me about question #1. A large part of the confusion is that one variable label is missing (it has since been added):
( P ) = Price level GDP [%]
This is not a CPI variable, it is a (kind of) GDP deflator. Regardless, use this as your price level variable when answering question #1.
There is another point of confusion about the c, i and g variables. Again, as the labels state, these are in percentage share of GDP (the variable RGDPL). Use RGDPL when converting the shares into levels. When you have the levels of c, g and i you can calculate the growth rates of each of these variables.
I have also had a couple of students confused over question 1d (the calculation of nominal growth rates). This is something we have done before and I cannot walk you through it. Hopefully, with the clarifications above it will be more obvious how to answer this question.