I'm looking for an alternative way of saying "You can't run before you can walk."
This is equivalent to saying "you can't take on higher level things before you have mastered the basics".
I am looking for either a rewording of the original phrase or a whole new phrase with the same meaning. I prefer that this not have any fancy words nor leave the reader scratching her or his head. I will use it in a semi-informal tutorial for future students of a programming class I am in. I use a short phrase at the beginning of each section which establishes the underlying theme in that section. This tutorial is meant to be something fun (and useful) to read, which is why I want something that catches the attention of the reader.
For my purposes, there is nothing wrong with the original. I simply want something that is a bit more inclusive (some people can't walk or run).