They are all very colorful and cute. Meanwhile, I suggest adding some natural perches from nearby tree, swing to play, stairs to climb.
This 6to 7month of age is still very young.
From the photos they are all friends or siblings. Paired lovebirds sit in pair keeping away from others.
You are kindhearted, but I am sorry that the store did not inform you well.
The good news.....
....they have not paired up, no fighting for space, still can be single out to bond with you.
....You will also need to ask some one at the store to tell you which is male or female. I was told that female are more aggressive, more difficult to tame, and may lay eggs with out partner, called chronic egg laying. So I suggest you choose one male to bond with.
....if you are keeping 2, then 2 males. Some people do. They probably won't fight since they grow up together. But who knows, I wouldn't do this. They may either fight and need 2 separate cages. Or they may bond and neglect you.
The bad news.....
......at the age of 10th month, they are likely to fight to pair up.
.....as they fight among themselves, add at least 3 set of food/water bowls, this way identification is easy. A couple that eat together has paired. The one chased away had lost the fight.
......Now weaker ones may be starve, so the need for extra food bowls. But they may bleed and need a separate cage. Quick separation will be needed before the need to take injured one to the vet arise.
......Keeping a paired birds will result in 4 to 5 babies per season. I would worry about this.
.....paired bird mate for life
.......Would it be possible to return some of them to the store? Or give them away in pair after they have paired up? Perhaps some family would love to watch growing baby birds?