Hello, depending on if your old Mac is on the same network as your new Mac, you could connect to it and open the file that way.  Or, you could copy the file across your network to the new Mac and open it there.  If the systems are not on the same network, you could copy the file via a USB stick from one system to the other system.  And a last option if you want or have an iCloud account, you could upload it to that and then download to your newer Mac.  Those are the easiest methods to move the file from one system to another.