Welcome to the forums and the ever exciting world of budgie ownership!
You have certainly come to the right place as you will find all you need to know on budgie care here.
Since you are new to budgies, the information on the several articles and sticky threads at the top of each section of the forums will be extremely useful as you become more acquainted with the species.
From the first picture, I can tell you the first two budgies on the left are young females, the third budgie is a male and the 4th one (green one) is likely a female as well. On the second photo I'm seeing a lot of white on the cere and prominent white circles around the nostril area.
All of your budgies are very young, I'd say they are fresh from turning 3 months old. By looking at them if they were bought at the same store, they are very likely clutch siblings. Especially the two budgies on the left and the one on the far right. Strict measures must be taken to prevent unwanted breeding behaviour: https://talkbudgies.com/budgie-breedi...want-eggs.html
You will have to pay close attention to their behaviours, because with a steeper difference in gender, you will run higher risks of running into trouble by housing all of them on the same cage. For your situation, it would be best to house two budgies per cage.
This link may be of use: https://talkbudgies.com/articles-gene...en-flocks.html
Best of luck with your new little friends!