The first step in first-level analysis is the creation of an "analysis". The analysis is a collection of information about how you want to analyze the functional data. This includes the specification of the input data, event types, event schedules, hemodynamic model, nuisance regressors, etc.

The First-Level Analysis (FLA) consists of:

Configuring the FLA is performed with mkanalysis-sess -gui

Please visit First-Level Analysis on FsFastTutorial for details.