"Blue Train" is a straightforward 12-bar blues that can be a vehicle for adventurous "outside" playing.
In typical blues tunes, most of the chords are "dominant 7" chords, or perhaps "13" chords that are like a dominant 7 with the 6th added on top. In this tune, most of the chords are "7 sharp 9" chords. These chords are common in funk music, but mostly used in jazz rarely for special emphasis. But here we have them running through the entire 12-bar pattern.
The key feature of the "7 sharp 9" chord is that it is ambiguous between major and minor. It has the major third in the main octave and has the minor third (aka sharp 9) an octave above. The difference between those two notes is a major 7th, which gives the chord extra tension. So as an entry point to playing a little more outside, you can experiment with mixing some major and minor scales into your lines.