If I had read this post first, I wouldn't have asked what kind of birds you had in your other post. Sorry.
Three months is a fairly young budgie. Maybe even too young to accurately determine whether they're male and female. It's possible but not probable that there's something physically wrong with the male. Hopefully, his lack of a tail is indicative of his young age, his activity level, and/or crowded conditions where it was plucked or trampled on by other birds. It might take a few weeks/months to grow back. In the meantime, he can't fly properly without his "rudder" so make sure that he is never in a situation where he might try flying outside of his cage.
Budgies are wonderful talkers but these two are too young to expect them to start for a while yet. First, you need to earn their trust, tame, and train them. I would suggest that you read the following material:
That one's about nuturing guidance.
That's about socialization.
And that's about biting, which you might encounter.
Since you just got these little guys on Thursday, your time now should be spent getting acquainted -- by standing or sitting by their cages and talking to them; letting them settle into their new environment; making sure that they have the best diet, cage, and toys; and learning all you can about their needs, their behavior, and their abilities. Time, patience, love, and knowledge will help to produce two wonderful friends who will delight and amaze you, I'm sure.