A bit of background reading will get you familiar with CrossFit terminology, exercises and training protocol before your first session.

The best source for this information is the CrossFit Journal.

Searching chronologically, you will find classic articles that are free to download in the earliest editions of the Journal.

The CrossFit method is explained by its founder, Greg Glasman in this article from April 2002 - “Foundations”.

His rationale behind the first named workouts is explained here in “Benchmark Workouts”.

There are many more great FREE articles.  How great is that?

You will need to complete a Pre-Exercise Questionnaire prior to starting your first session. 
Health_History_Questionnaire.pdf