brand new macbook stuck in boot loop

You can erase it, which will result in your brand new MacBook behaving exactly as it did when you unboxed it.

Follow these instructions, or as much of them as you can: What to do before you sell, give away, or trade in your Mac - Apple Support. Since your Mac won't boot, start with Step 7.

Or, avail yourself of Apple's complimentary 90 day phone or chat support: Contact Support.

You shouldn't have to cope with these difficulties. You already paid Apple for that service by purchasing a new Mac, so why not put them to work.