how to download software to MacBook for Printer Canon iP 1500?

Click on this link to the Canon support for the iP 1500.

https://www.canon.co.uk/support/consumer_products/products/printers/inkjet/pixma_ip_series/pixma_ip1500.html?type=drivers&language=&os=macos%2010.14%20(mojave)

Make sure the operating selector is set for the correct macOS you are using.

You can see that your printer is not compatible with macOS Mojave.

The last mac operating system it was supported under was Mac OS X Snow Leopard (10.6)

which was a very long time ago.

Have you just upgraded to macOS Mojave, and if so from what OS.