This is not an exam, there is no jury that's going to give a mark to the song we create, I see it as an exercise to improve my skills. When I was learning improvisation on the saxophone, my teacher made me improvise first only with 2 notes, then 3, then 4, ... until I was comfortable enough to improvise on that scale, then moved on to another scale, ... Any musician will practice every day and do exercises ( scales, fingering technics, ... ). It's vain from your part to think this is stupid.