Suggestions for using arduino mega to power multiple devices

Doing my first Arduino project for a work project. Going to be using an Arduino mega to control two stepper motors. I've got a L293D shield I plan on using and a Piezo beeper I would like to attach elsewhere. I also want to be able to power each cycle to start when a button is pushed.

What I'm struggling with is setting everything up and then implementing the button and speaker. The motor driving is actually going fine so far, just curious if anyone knows how to do all of this at once and can maybe point me towards some resources where I can learn how to do it in about 5 mins or less as that's about the kind of time I have to work on it.

What ever that is, put it in a function and call the function whenever you want.

That tells that M3 screws are used to fit the motor and dimensions for the hole pattern. No electric parameters are tied to Nema ....
There's quite a risk You can't run that stepper with that driver.
Please post a link to the stepper datasheet.

You cannot use a Mega or any Arduino board to power any but the tiniest of motors, Arduino boards are micro-controller, not power supplies. You need an appropriate power supply for the motor. Your Mega is more than capable of controlling the motor.

If you provide details of the motor someone will most likely suggest a suitable power supply.

As for the bit about repeating things, this is basic programming. If you don't know how to do it then work through the tutorials on this web site, in the Arduino IDE and elsewhere. Make an attempt at what you want to do and post your code in line with the forum instructions How to get the best out of this forum . If you make a decent attempt and get stuck someone will help.

Lots of people had done similar projects to you and had help here, probably the best place to start is by reading through existing questions and answers in this section of the forum.