Unable to reinstall macOS on an older MacBook

First, you should state why you are unable to install the OS. Otherwise, we have no information to evaluate and then respond to. What happens when you try? Are you receiving a message? Please tell us why you need to reinstall the OS. You have access to Disk Utility so you must still have a working OS. Here are some points to consider.

• Ethernet is more reliable than Wi-Fi and it is much faster. Using Wi-Fi will often result in corruption to the downloaded file. If it is the only mode available, then you may have to download multiple times until you get a good file than can load properly.
• A 2004 Mac is very old and no longer supported. It can only run a non-supported OS high will no longer be compatible with the current offered app downloads, so its use will be very limited at best.
• Many of the older OS's are no longer offered on the Apple App site. I'm sure that yours is one of them. So, you may need to do your OS installation from a disk.
• If you followed the Apple instructions for clearing a Mac before giving it away, reinstalling the OS shouldn't be necessary.

What to do before you sell, give away, or trade in your Mac - Apple Support

blueiriseditor wrote:

After clearing my 2004 Macbook ...

There is no such model. The oldest MacBook is a 2006 model, for which you will absolutely require its original discs to reinstall its original operating system.

Please clarify. We can't get past those few words until you do.