You are your best teacher (besides our heavenly Rabbi.)
Study the definitions for the new terms introduced to you in Chapter 6.
Study and go through the questions and answers in Lesson Practice (LP) 6A again and again.
(YouTube a video about these types of angles if you want further explanation.)
Complete LP 6C (Friday) and LP 6D (Monday).
Also write the 9 postulates listed in this post.
Errata: #5: If two angles have equal measures, they are congruent.
ADD #9: Two angles who measures add up to 180 degrees are supplementary.