Bootable installer difficulties - createinstallmedia command not found

Hello

I recently found my old MacBook Pro 2009 that I have no use for, and plan on selling it or giving to a family member. The hard drive has since kicked the bucket, so I purchased a new SSD, and I am trying to create a OS X El Capitan installer. The original Snow Leopard disks have since been lost.

However, every single time I attempt to do this, it gives me the same error: create installmedia, command not found. I can't open InstallMacOSX.pkg without starting the installer because I can't for some reason open the package's contents. I am creating it with my Mid 2011 iMac running High Sierra. Also, I can't even find the .app file, because it is a .pkg file, and again, the issue mentioned above.

Here is an example:

For an easier read: sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/elcapitaninstall --applicationpath /Applications/Install\ OS\ X\ El\ Capitan.app

Am I typing in a wrong command? Any Google, Apple Discussions, MacWorld, Apple Support, etc. results land me back to square one.

Regards,

mdp1101