One of the difficulties with a self-directed education program is that it's easy to begin with a burst of enthusiasm, but harder to keep it going when there aren't immediate rewards. Then again, there are many other such projects, such as weight loss, housecleaning, and practically anything else that takes longer or costs more than you had anticipated. The costs of a self-education project aren't so much monetary as in the form of time and other opportunities that may need to be sacrificed.
Social structure and change includes a significant part of sociology and anthropology. I have three principal divisions.
1) Social structure. This deals with the group structure of society. It may include, for instance, the distribution of people (urban or clustered, or rural and dispersed). There are social categories such as men, women, children, the elderly, and racial or ethnic groups, and there classes based on economic status. For societies with more than one community, the distribution of communities also belongs to this grouping.
2) Social types. These include categories based on the means of subsistence; for instance, hunting and gathering, horticultural, pastoral, seafaring, agricultural, and industrial societies.
3) Social change. These include things such as generational change, artistic styles, inventions, and the various mechanisms by which innovations are adopted, or fail to be adopted, by a society. I also include changes in society such as migration or settling, industrialization, modernization, and urbanization. Specific social movements, such as temperance, abolitionism, or world commmunism, to pick just a few examples, also belong here.
These are toward the opposite end of the scale of knowledge from the natural sciences, which are not as directly useful as they are in other areas. However, these depend heavily on leaders and prominent figures. These areas depend on and are sometimes hard to separate from social fundamentals such as social psychology, demography, and physical anthropology. Cultural elements such as idealogy and philosophy, customs, and objects are both products and instigators of social change, and the institutions of families, education, economics, government, and religion are all important. History is also useful in exploring the background and consequences of social structure and change.
It's difficult to make a specific assignment in this area, since there are so many possibilities and levels of involvement. Pick your own subject and try to consider it from a social point of view.