We've had our parakeets, Roger (green) and Amelia, for about a month now. They're still pretty scared of us, but we're trying to get them used to having us around. (Ignore the wine bottles above, they're used to prop up the branch - we don't have alcoholic 'keets)
We mostly leave the cage open and they stay within a small area of our TV room. They tend to fly back and forth from the sliding glass door and back towards their cage. We made them a tree out of a maple branch too. They love to hang out in there and climb all around it.
They also seem to be getting a little frisky lately. Roger will dance around Amelia and then try to stand on her tale (trying to procreate perhaps?). His dancing is hilarious and I'll try to get it on video. We got them a lot of toys, but they seem to be pretty happy just playing with each other most of the time - preening, fighting, sharing food, etc.
As for eating, they love their seed and their spray millet. We've also given them celery, carrots, spinach, and watermelon which they seemed to love. Cherries are not on their list though. We tried, but they tossed them out of their food bowl.
I'll keep you posted on any new developments.