failed High Sierra Install on Late 2011 MacBook Pro

Your 2019 mac would have come preinstalled with an OS newer than macOS High Sierra.

Probably macOS Mojave or macOS Catalina if it is a late 2019 model.

Macs cannot run an older OS than the one they came preinstalled with, so if you put

High Sierra on an external disk you will not be able to boot your 2019 mac to that drive.

If your intention is just to use this drive as an external storage disk for the 2019 mac then

it does not need an OS on it, you just need to erase it and format it as Mac OS Extended (Journaled).

If you have the Install macOS High Sierra.app on your 2019 mac then you should be able to

make a bootable USB flash drive (16GBs or larger) using Terminal and the createinstallmedia command.

Put the Install macOS High Sierra.app in your Applications folder.

Now read these instructions,

How to create a bootable installer for macOS – Apple Support

Having made the bootable USB installer you're ready to erase and then install a fresh copy of El Capitan.

The USB should be plugged directly to your mac. 

Restart the mac while pressing and holding the option/ alt key.

In minute or two you will see the Startup Manager, select the USB and press Return.

When booted to the USB you will see a Utilities panel, select Disk Utility and press Return.

Click View in the menubar and select Show All Devices

In the left hand panel highlight the Disk (Samsung SSD…) not any indented Volumes.

Click Erase.

Give the Disk a name.

Format: APFS

Scheme: GUID Partition Map

Click Erase.

When Done quit Disk Utility.

Click on Install OS press Continue the installation process should start up

follow the prompts.

Does holding Option key at startup show more boot choices?

Can you erase the drive from Restore mode?

Repair a storage device in Disk Utility on Mac

Disk Utility can fix certain disk problems—for example, multiple apps quit unexpectedly, a file is corrupted, an external device doesn’t work properly, or your computer won’t start up. Disk Utility can’t detect or repair all problems that a disk may have.

If you run First Aid on a disk, Disk Utility checks the partition maps on the disk and performs some additional checks, and then checks each volume. If you run First Aid on a volume, Disk Utility verifies all the contents of that volume only.

1. In the Disk Utility app  on your Mac, choose View > Show All Devices.
2. Note: If you’re checking your startup disk or startup volume, restart your computer in macOS Recovery, select Disk Utility in the macOS Utilities window, then click Continue. If you check your startup volume (Macintosh HD), make sure you also check your data volume (Macintosh HD - Data).
3. 
   
4. In the sidebar, select a disk or volume, then click the First Aid button .
5. If Disk Utility tells you the disk is about to fail, back up your data and replace the disk—you can’t repair it. Otherwise, continue to the next step.
6. Click Run, then click Continue.
7. If Disk Utility reports that the disk appears to be OK or has been repaired, you’re done. You can click Show Details to see more information about the repairs. Otherwise, you may need to do one of the following.

• • If Disk Utility reports “overlapped extent allocation” errors, two or more files occupy the same space on your disk, and at least one of them is likely to be corrupted. You need to check each file in the list of affected files. Most of the files in the list have aliases in a DamagedFiles folder at the top level of your disk.
    • If you can replace a file or re-create it, delete it.
    • If it contains information you need, open it and examine its data to make sure it hasn’t been corrupted.
  • If Disk Utility can’t repair your disk, or you receive a report that the First Aid process failed, try to repair the disk or partition again. If that doesn’t work, back up as much of your data as possible, reformat the disk, reinstall macOS, then restore your backed-up data.

If your Mac has a Fusion Drive and you see a flashing question mark or alert, see the troubleshooting section of the Apple Support article About Fusion Drive, a storage option for some Mac computers.

If you continue to have problems with your disk or it can’t be repaired, it may be physically damaged and need to be replaced. For information about servicing your Mac, see Find out how to service or repair your Mac.

In Terminal…

diskutil resetFusion

MexRaider wrote:

If I boot holding the alt key I get a picture of a hd and a box to choose a wifi account. After filling in the internet account I press enter and get booted to a screen with a circle with a line through it. If I boot in recovery mode disk utility first aid indicates no problem with disk but it won't erase because it won't unmount

If your goal is to erase the existing storage, you will need to boot from Internet Recovery if your Mac supports that, or you will want to build and boot from a bootable installer as was mentioned earlier. You can't erase the device that you're running macOS from.

Here's that link again, with related info: How to create a bootable installer for macOS – Apple Support

You may need to Format the driveMacOS Extended in older Macs & let the Installer convert it to APFS.

Start up from macOS Recovery

To start up from macOS Recovery, turn on your Mac and immediately press and hold ...

Command (⌘)-R

Installs the latest macOS that was installed on your Mac.

Did maybe this part get missed? If you can't start up from the bootable installer, make sure the External Boot setting in Startup Security Utility has been set to allow booting from external media.