How can I install Windows after messing up my Linux Mint installation?

It seems like your SSD has a Linux partition that the Windows installer doesn't recognize. You'll need to boot from any Linux live media, preferably a different distro, and use a partition tool to wipe all existing partitions on the SSD. Just give it a fresh start as a blank disk. The Windows installer can handle creating the necessary partitions during installation more effectively afterward. Also, consider disabling secure boot before you try again!

If you're still open to exploring, trying out a few more distros might help! But if the clock is ticking, I'd suggest going with Ubuntu; it's generally easier to install than Windows. When I switched to Linux, I had a similar experience with a messed-up install and ended up trying a bunch of distros before settling on one that fits me best.

I suspect you're running into a driver issue; the Windows installer might not have the necessary drivers for your motherboard's storage controller. You can download those drivers from the manufacturer’s website and then, when you're at the point of selecting the drives during installation, look for an option to ‘install driver’ to help Windows recognize your SSD.

Honestly, if you can get hold of a Windows installation media from a working Windows PC, that's the way to go! Download it from Microsoft's website, create a bootable USB, and reinstall Windows from there. After that, you can look into dual-booting with Linux Mint. By the way, if the laptop is brand new, Mint might not be the best option; something like Manjaro might work better for you!