Advice for knocking back and organizing BlackBerry vines?

I planted a few vines last year in the corner of my yard…. Some have (sharp) thorns, some are thornless.

I’ve been out of town all summer and came home to this…. It’s blowing up

How do blackberries grow? What vines should I cut down and back?

Advice for staking these out to make it more manageable and accessible?