Young New Driver :

If your car rental charge extra for the new or young drivers then you can select this option, otherwise leave it blank.
First option is about the experience of driving and you have to enter the no. of years, e.g Less than 2 years etc..
Second option is about the age of the driver in this option you have to decide that less than this age of customer is considered to be a young driver. e.g 20 years of age is knows as a young driver.