The difference between Micro and Macroeconomics is simple to understand and the hint is in the name!
Microeconomics is the study of economics on a 'small' level: at an individual, firm and market level. This could involve examination of demand and supply models of a certain product or behaviours of individuals and firms and their effect on each other and the wider economy.
Macroeconomics on the other hand is the study of economics on a 'larger',wider level: issues that affect the economy of a nation as a whole. This could involve the study of for example inflation, unemployment and exports/imports.