Sightreading is high speed pattern recognition. Pattern recognition comes from knowledge of rudiments and theory, piano technique, aural training, a deep knowledge of music history and stylistic performance practices and playing experience. A trained musician does not see a series of notes, they see patterns and relationships. For example, Mozart Minuet in G K 1e.
If I can help you, call me.
You've got to learn your instrument. Then, you practice, practice, practice. And then, when you finally get up there on the bandstand, forget all that and just wail.
I'm a professional pianist and music educator in West Toronto Ontario. I'm also a devoted percussionist and drum teacher.