My new MacBook pro refuses to boot up.

Yeah, something like factory reset, it's a reinstall. Let's assume your Recovery Partition is still there, so you must restar your Mac while holding Command R, enter recovery mode and select reinstall macOS.

My advice would be for your to make a clean install with a bootable drive. Use your iMac to create it as Apple says here https://support.apple.com/en-us/HT201372, load the recovery mode and reinstall.

You can also completely erase the disk and make everything entirely new https://support.apple.com/en-us/HT208496

Reinstall macOS https://support.apple.com/en-us/HT204904

And, of course, as you're still within the 90 days of purchase, as sais TheLittles just above, you can call Apple Support and get the guidance through the whole process.

It would be nice to know the exact model and specs of your Macs.

Second, try booting in Safe Mode by turning on the Mac while holding Shift. If everything runs well, restart normally and see if it boots. If Safe Mode or normal boot after fails, your macOS install is gone and you'll have to reinstall it.

I have to say: don't waste your time with it and simply reinstall macOS and do a manual setup.

Migration, Time Machine, that's all made to drive you insane.

Never, ever, use wi-fi to make this kind of things. You can easily loose signal and it might be changing system files at the time aaaaand... Crash! Gone!

Plus, this methods can bring old junk to your new Mac or install and also bring back some problems you've been trying to get rid of by formatting your Mac.

Beejp Said:

“My new MacBook pro refuses to boot up.”

———-

Perhaps this is a Faulty Device?:

I insist that you stop fiddling with it, and call Apple back. You said “yesterday,” my my question is: How old is this Mac? If it is purchased directly from Apple, and it has been less than 14 days since the transaction went through, then contact Apple. Request either a swapout, or full refund.

Note:

If more than 14 days, You have a one-year, out-of-the-box, limited-warranty. So, contact Apple Support and request a swap-out. Right now, there is Send-in Service, available, if no Apple Store is open.

Apple Contact Us:

--- Contact Us - Choose Locations

--- USA: 1(800)MY-APPLE

--- Proceed from there as Necessary

How Send-In Service would Work:

1. They’d: ship you a box
2. You’d: ship it back
3. They’d: look at it
4. You’d: get a new one, if approved.

NOTE:

Due to the Coronavirus Pandemic, calls are taking a bit linger to get through. And, that makes sense, because many are at home working out-of-the-house or are taking classes over-the-web, thus they have more time on their hands to contact Apple Support. So, it might take a bit to get through to Apple Support. But, just stay on the line, and someone will be with you.

Beejp Said:

“My new MacBook pro refuses to boot up.: [...]I only purchased this yesterday and am feeling really irritable given apple will not provide support - can anyone help with this please??????”

———-

Call Apple Back, Screensharing your iPhone:

What you mentioned doesn’t sound like Apple! I would call again, asking to speak with a Apple Senior Advisor. A great tip would be to show the Apple Staff what is happening firsthand by screensharing the camera of your iPhone.

A. Apple Phone Support Info:

• Contact Us - Choose Locations
• USA: 1(800)MY-APPLE
• Speak with: Apple Store Staff
• Proceed from there as Necessary

B.  Screenshare: Consider performing a screensharing session on your device, so the Apple Rep can see this firsthand, from your perspective.  Learn More Here: Screenshare your iPhone with the Camera App Enabled to Easily Converse Over-the-Phone with Apple Support

C. Chat Session Info:

Being that phone calls are taking a moment, perform a chat session with Apple Support.

Setting Up the Chat Session:

1. Go to: support.apple.com
2. Scroll Down to "Tell us how we can help"
3. Select: Get Support
4. Proceed from there as Necessary

D. Note: Phone Calls are Currently a Wait:

Due to the Coronavirus Pandemic, phone calls are taking a lot longer than usual,m. And that makes sense because with many-out-of-work, and many home-from-school, phone calls will likely take a while to go through — so, just stay on the line, and an Apple Senior Advisor will run you through the fix. Chats are taking a bit longer.