A little confused about the statements regarding the 555. This chip has no memory, if that's what you were meaning. To design an oscillator with variable duty cycle control is no big deal. In fact, if you refer to the data sheet,
https://www.electro-tech-online.com/custompdfs/2008/09/LM555-1.pdf,
you will find applications for an astable and PWM circuits. There's nothing to program unless you are using a trigger to "fire" the timer using a µC. Perhaps this is what you meant by programming and the .hex file that was provided to you. If your a novice and can read a schematic, as a novice, you shouldn't have any problems.