I’m going to break up my counterpoint p0sts to make it easier to find the information you need to understand and complete the exercises.
Counterpoint literally refers to note against note, and is used to describe musical textures with two or more independent lines sounding together. Although we generally refer to two historical periods as the primary times for great contrapuntal music, the notion of how music moves linearly is a fundamental basis of music throughout the common practice tonality. Haydn, Beethoven, Mozart, Schubert, and many other composers have studied counterpoint extensively as part of their musical instruction.
Species counterpoint is a strict and graduated method for learning to write counterpoint. The method makes use of several over-riding principles, which lead to fairly strict rules that govern each step of the process. The idea is that you start with simple material, expanding what is possible over time as you master previous steps. You should also note that species counterpoint as a whole is a learning method for the teaching of compositional skills, not the teaching of composition as a whole, and is historical in nature.
Full instruction in species counterpoint is well beyond the scope of Theory 1. What we will be doing is working briefly through the first few steps: melodic writing, note against note (1st species), and two notes against one note (2nd species). The goal of this work is better understand the linear aspects that govern melodic and harmonic movement in the tonal music we will study through the first two years of theory study.