I’d leave all the runners in place until some pumpkins set and if you’ve got the space, just leave them or trim back the ones without fruit if they are getting in the way. The more leaves, the more energy to grow the pumpkins. Whether you thin the pumpkins depends on why you are growing them. If you are after a monster then best to thin to one, but otherwise just leave the plant to sort itself out. It’s a bit worrying that you’ve had no female flowers yet, it’s the same on my butternut squash, although the ulrichi Kuri are getting to a good size already. Just a strange season. Good luck.
