Couple of things:
Move out of P mode into A mode. This will allow you to control your aperture and the let the camera pick the appropriate shutter speed to match. In this case, with such a busy background, you want to separate your subject from that background, so set the aperture wide open for whatever lens you are using, make sure your subjects are both equidistant from the lens, and fire. If you find that you need more depth of field, pull the lens down 1 stop and fire again.
To me, this shot looks pretty unusable, there will be no way getting around the focus issue (the subjects are clearly out of focus, the background is sharper than the subjects). The brightness level is fine ... their faces are correctly exposed and that's all that matters.
As far as shooting outdoors on a bright sunny day, I have a recommendation for that. Shoot into the sun. Put the sun on your subject's backs, and use fill flash to brighten them up. If you have an SB-800, use the orange filter over the flash head to warm up the color a bit. Overhead sun can act as a great hair-light, I put the sun to my subjects back to avoid harsh shadows on their faces and keep them from squinting. I have no examples online right now and I'm at work, but if I remember tonight I'll post a few examples.
If you don't have a hot-shoe mounted flash, but you have 30 seconds to do a little shot setup .... bring a piece of white foam board with you and set it up in front of your subjects to bounce a little natural light back at them. Even better, if you have some spare while paint primer around and a large piece of cardboard .... paint the cardboard. It will work just as well and have the added benefit of being fold-able for easy storage and transportation.
Bill