There’s nothing much here to challenge you. It is an attempt to orient the reader generally to the subject of statistics. Generally these "orientations" (like "outlines" of papers you are attempting to write) do not help a beginning student because they make little sense until after the subject has been learned. To some, they belong in the category of things that are COIK, i.e., Clear Only If Known. The more important notion to be got across at this early stage is how the subject of statistical methods is organized. This diagram may help:

    In descriptive statistics, our objective is to describe the properties of a group of scores or data that we have "in hand," i.e., data that are accessible to us in that we can write them down on paper or type them into a spreadsheet. In descriptive statistics we are not interested in other data that were not gathered but might have been; that is the subject of inferential statistics.     What properties of the set of scores are we interested in? At least three: their center, their spread, and their shape. Consider the following set of scores, which might be ages of persons in your bridge club:
28, 38, 45, 47, 51, 56, 58, 60, 63, 63, 65, 66, 66, 67, 68, 70
    We could say of these ages that they range from 28 to 70 (spread), and the middle of them is somewhere around 60 (center). Now their shape is a property of a graph that can be drawn to depict the scores. If I marked the scores along a number line, like so

    In inferential statistics, our interest is in large collections of data that are so large that we can not have all of them "in hand." We can, however, inspect samples of these larger collections and use what we see there to make inferences to the larger collection. How samples relate to larger collections of data (called populations) from which they have been drawn is the subject of inferential statistical methods. Inferential statistics are frequently used by pollsters who ask 1000 persons whom they prefer in an election and draw conclusions about how the entire state or county will vote on election day. Scientists and researchers also employ inferential statistics to make conclusions that are more general than the conclusions they could otherwise draw on the basis of the limited number of data points they have recorded.