To familiarize yourself with something means to learn about it well enough that it no longer feels strange or confusing. When you familiarize yourself with a new school, you learn where the classrooms are, figure out the lunch routine, and get to know some teachers and students. What felt overwhelming on the first day becomes comfortable and manageable.

When you familiarize yourself with the rules of chess, you study how each piece moves until playing feels natural. A doctor familiarizes herself with a patient's medical history before treatment. A traveler might familiarize himself with basic phrases in another language before visiting a foreign country.

Teachers often tell students to “familiarize yourselves with the test format” before a big exam, meaning you should practice enough that you know what to expect. The goal is to transform the unknown into the known, turning confusion into confidence through steady practice and exposure.