Green sunnies, like most fish, will eat smaller fish that can fit in their mouths such as guppies.
To transport, just get a bucket or other container of suitable size. I often use a smaller cooler. If you are concerned about leaking/splashing water, you could put a bag such as a trash bag in the container and tie if off at the top. Most important, you need an aerator to actively replenish the DO in the water or the fish will not survive long. If it is a short trip from your fishing spot to your house, hydrogen peroxide can get you by in a pinch but it will also be more stressful. Good luck and happy fishing