Economics consists of theory and economic data analysis. The former consists of Microeconomics & Macroeconomics, and the latter is econometrics. Microeconomics studies how to interact between consumers and firms. Before 1980s, the target was market institutions which give prices. Then, economists were interested in how both the consumers and firms make decisions when they observe prices as signals and how the prices are decided depending on market structure. However, since game theory developed after 1980, the theory succeeded in analyzing their decisions and behavior without prices. Then, the analysis by Game theory is parts of microeconomics now. SILS provides two classes of Microeconomics, Introduction level & Intermediate one. If you select to study economics, Introduction level is too easy. You directly join the class of Intermediate level of Microeconomics. And the following textbooks are recommended: H. Varian (2014) Intermediate Microeconomics: A Modern App...
A guidance to study Economics in SILS, Waseda university.