@Jeanette, Chris has done a great job with this IOTM, because it helps you to build fundamentals. You can only really progress if you have solid fundamentals, and if I may be so bold, in order to improvise freely in the jazz idiom, a knowledge of triads and facility with triads on the instrument is essential. It is well worth practising major and minor triads first. Do them round the cycle of fifths, chromatically up, chromatically down, down in tones (whole steps) up in tones (whole steps) and so on. Mainstream jazz is based on Classical Triadic Harmony, forget quartal harmony for the time being. Make sure that you play each triad in every inversion, Root, First and Second Inversion.
Once you are comfortable with this, then set your metronome at a steady tempo say 60 bpm and play through the triads. You can play triplets, or 1351, 1353 and so on. Also start at any note and play all triads up and down from the note that have it in it. You can later on extend your study to diminished and augmented triads, but leave that for now.
If you have played through the cycle of fifths, then you have played triads for every possible ii V I there is (e.g. in C major, the triads are D minor, G major and C major). This gives you a good starting point. Later on, you can use the triads to play rootless voicings such as G major to represent C maj 9 (G, B, E of G is 5, 7, 9 of C). All this without even playing a four note seventh voicing.
We'll come to scales later, but that is another topic.
Hope this is not too simple for you.
All the best, Bill