How should I partition MBP w/8TB of SSD

In the new OSs, and I'm assuming your machine came with Monterey installed, the drive has a container. Inside the container are two volumes. One called Macintosh HD and another called Macintosh HD - Data. You can't touch the first one. It contains the system and the system installed applications, except for Safari. The data volume takes up most of the drive, that holds your stuff, and that's what Time Machine backups up normally. You can create more volumes by clicking the + button in Disk Utility.

Volumes are not like partitions. You don't specify a size. The volumes use the space in Data, and can grow and shrink as the contents of the volumes change, until the volumes fill the Data space. You can specify in Time Machine System Preferences which volumes you want to exclude from the backup using the Options button. You click + to add the volumes to exclude.

That's basically it. There is no advantage or disadvantage to making additional volumes except for organizing. If you delete the volume in Disk Utility with the - (minus) button the volume and its contents will be erased from the drive.

Your internal drive is formatted as APFS.

APFS makes partitions mostly unnecessary, as there is a better way. You can create additional volumes within the same APFS container. These volumes share the available space in the container and, unlike with partitions, you don’t need to specify a size for each.

So congratulations on your new mac, and create one or more volumes to organize your media as you see fit.

Yes, the ability to use Time Machine with your Macintosh HD, while having a separate backup strategy for media volumes, is one good reason to have separate volumes. And by creating them inside your APFS container means you never have to worry about how to size them.

I also have thought about this as these internal SSD are so fast and I Usually edit off of an external drive usually in a 8 terabyte raid - But seems like a good way to go considering SS D’s externally are pricey anyways why not have an internal partition 2 TB for the main operating system 6 TB for editing projects

There is no reason at all not to treat the drive as a single volume, unless as Luis said you have a reason for organizational purposes to divide the drive into separate volumes.