I cut most of the top vine growth, but left some. So I can decide on how to train it. The rootball is about 1.5' wide and I kept a couple of extra long roots that I saved.

At the base, there are two main canes. I think to train the vine, there are a few ways I can do:

1. Aggressively cut the vine to a long single stick. This will be the central trunk and I can grow the arms.
2. Keep two main trunks and train two arms from each trunk;
3. Save some canes as the arms for this year. Continue to train them for next year. I'm not sure about this.

I think since this is the first year, I should be on the aggressive side and cut a lot of the old growth. I do plan to leave one cluster to see what grape this is.

Or could retain just one sturdy cane, then train as suggested in this pub at the link below ..
In other words, handle that one cane as if the vine completed a year's growth.

One exception would be a fan arrangement in which case you can use all of those vines. (see link for ideas. For a home owner I don't think there is a right or wrong or one way to do grapes. Yours is out in the open so will need some form of support. The doc is for commercial production outside your residence so some of what is said does not apply.)

Nice looking vine BTW!