Interactively inputting data, assigning limits

I have zero experience in programming and am just starting For my COP3014 class, we have to write a program that accepts as input a pollutant number (integer), a number of grams emitted per mile (real), and an odometer reading (integer), and then prints an appropriate message indicating whether or not the emissions meet or exceed the legal limit for the vehicle. I kind of have the idea of it but I have no clue where to begin on the project.