Motivate by describing some prominent uses of CPI to find and work with real incomes and prices, wages etc. Then motivate from this why inflation is important and EXPLAINING PRICE MOVEMENTS and inflation is so important for the Fed and government policy, retired people etc.
There are two types of models for inflation rate: time series models or models with other explanatory variables (causal models).
Among the causal models, some account for EXPECTATIONS and some dont. There are, for example, old Phillips curve models and new ones. Meta means a collection of models and methods that are put together or examined together as a group.
You could say something about what it means to forecast.