where is my iPad backup on my MacBook Pro?

If your backing up to a Mac you can find the backup files with Finder -> Locate backups of your iPhone, iPad and iPod touch – Apple Support

In Catalina or Big Sur it is very simple since finder now handles the backups, it has tools to find and manage them as well.

donaldbj wrote:

I think I backed up my iPad to my MacBook Pro but I don't know where it is so I can transfer it to a new iPad. Where can I find the backup?

Restore your iPhone, iPad, or iPod touch from a backup - Apple Support