In this lesson, I'm aiming to primarily cover the areas of modulation, and counterpoint.
As a quick first lesson, I want you to write some first species (note against note) counterpoint to the cantus firmus provided here.
Just to go over those terms incase you're not used to them. First species counterpoint is writing a melody against another melody, using the same note values for the counterpoint as are used for the cantus firmus(C.F.)
The C.F. is the musical line used in counterpoint studies, against which you set your counterpoint. For first species, if the C.F. is in semibreves, then your counterpoint is in semibreves.
I will see how you do here, and then introduce modulation, and the later species.
I want you to take this phrase:

and compose a bass part for it.
Counterpoint is the art of writing melodic lines against one another, and very much keeping them as individual lines! That is, each must move logically, and like a melody line in it's own right. I don't mean each has to have a memorable tune, I mean each must move melodically and must not jump about to fill in the harmony. By using several parts of counterpoint, you do fill out the harmony, and therein is the art of counterpoint, but the focus is on logical linear motion, while trying to properly imply the harmony.
Bear this in mind for your short exercise. It's only a simple one so I can see where you stand.
Try to keep an individuality of each voice or part; try not to leap too much, although the bass part inevitably requires more of this; do not write any 4ths between the bass and soprano, and similarly, no unprepared dissonances. (the 4th between bass and upper part is classed as a dissonance in this type of writing.)
I will see how your exercise goes, and then see where we can move to from there.
If you have not understood anything, or I have not explained anything clearly enough, please post, and I will try to clarify.