Need help

i want to try writing a program. i want to start with a basic input value to decide on the amount of input needed. after the first input is enter, the second input is enable with a next button beside it. if my basic number is 3, i need to set my next button to work 2 time to collect all the 3 input. after that i need to use the 3 input for some calculation.Can someone advise me on how to go about writing the programme?
Thank you