Problem reinstalling macOS

When I go thro the install, it says about 6min remaining & at the end of 6min I get "An error occurred while preparing the installation try running this application again".

That's because macOS Sierra is no longer eligible to be installed. Please try the steps again, making sure to use Option-Command-R at startup. By doing that, macOS Ventura should be offered.

-Jack

Hey there!

If you use Internet Recovery mode to erase your Mac using Option-Command-R at startup, your Mac should offer to install the latest supported version of macOS for your Mac, which in your case is macOS Ventura and you should not see this issue. To try this, follow these steps:

1. Start up from macOS Recovery: Turn on your Mac, then immediately press and hold these three keys until you see a spinning globe: Option-Command (⌘)-R. 
2. From Recovery, verify your Mac is connected to a Wi-Fi network using the Wi-Fi menu in the top right of your screen.
3. From the utilities window, select Disk Utility and click Continue.
4. In Disk Utility, select View > Show All Devices. Then, look at the sidebar of Disk Utility and look for an entry titled "APPLE SSD...".
5. Now, on the selected entry, click "Erase", and enter the requested details:
   1. Name: Macintosh HD
   2. Format: APFS
   3. Scheme: GUID Partition Map
6. Now, click Erase.
7. When done, quit Disk Utility to return to the utilities window.
8. Select Reinstall macOS in the utilities window, then click Continue and follow the onscreen instructions.

After your Mac has reinstalled macOS, your Mac will restart to a setup assistant. From here, you can setup your Mac.

Hope this helps! Let us know if you have any questions!

-Jack