Ok, I'll keep it simple then.
You're starting on C, and all the notes you're using (C,D,F, Ab, Bb) belong to a C minor scale.(Specifically C natural minor, but it's not important) So this track is in C minor.
There's one note that doesn't fit, which is the C sharp. So, I'd recommend that you change that one.
Also, the biggest thing which makes C minor C minor and not C major is an Eb. You can tell from the Ab and Bb that come in later that it's in C minor, but as it's quite a long time before they come in but it's better to make it clear from the beginning by putting a few Ebs in there.