Create bootable CD / USB-Stick with Snow Leopard on it, from a dmg file

Read first:

I want to install OS X Snow Leopard, because a Chat Support Guy told me that Snow Leopard is required to install El Capitan on my iMac

(Important NVRAM and RAM Updates are included in Snow Leopard that are required by OS X El Capitan).

So if there is a way to skip Snow Leopard and go directly to El Capitan ignore all the other stuff written below. Im just trying to upgrade to El Capitan and not to Snow Leopard. If there is no other way than installing Snow Leopard then read the stuff below.

If there is a way to go directly to El Capitan please tell me because im really frustrated.

Hey! Im trying to install Snow Leopard on my old iMac but there seems to be a problem... I have a dmg of the Snow Leopard Update and when opened it, it says I should burn the image to a CD to then start the iMac from the CD. My only problem is, that all CD's that I have are only 4,7 GB or 700 MB big and the Update is about 7.5 GB. My question is:

Q: How can I create a bootable CD / USB-Stick with OS X Snow Leopard on it, from a dmg file?

Available Computers inside my Home:

MacBook Pro 2018 - macOS Monterey

iMac 2008 - OS X Leopard

Thinkpad - Windows 10

Side note:

I already tried the Terminal Codes that can be found by clicking here

I also have a question about these commands... I do not understand how they work. I replaced the /myVolume with the name of my USB-Stick. Also how to I know which one I have to pick?

For Example:

I want to create a bootable El Capitan USB-Stick. I have macOS Monterey installed on my machine. Which command do I pick? The command for El Capitan or the command for macOS Monterey?

CD burn Idea:

I don't know it it's possible but when I installed OS X Leopard I had 2 Installation CD's and while it was installing it told me to insert the second CD to continue the installation. Maybe it's possible to burn the dmg file to two separate CD's? I don't actually know if it works but I just wanted to mention it.

Disclaimer

I am not trying to install OS X Software to any-non compatible device like a Windows PC! This is just for personal restoration of my old iMac.

Thank you for helping!