i need 2 buttons to be pressed for a certain amount of time and if those 2 buttons where to be released i need it to stop the firing sequence and start over when the buttons a pressed again.
Sounds like a state machine with 5 states
state 0 : system idle. Change to state 1 if button 1 becomes pressed or state 2 if button 2 becomes pressed
state 1 : only button 1 is pressed. Change to state 3 if button 2 becomes pressed. Change to state 0 if button 1 becomes released
state 2 : only button 2 is pressed. Change to state 3 if button 1 becomes pressed. Change to state 0 if button 2 becomes released
state 3 : countdown. Change to state 0 if either button becomes released. Time countdown using millis(). Change to state 4 when countdown ends
state 4 : Fire. Activate the rocket