When I was in Basic Training (a few decades ago), I kept in mind that these people (TI's) were just like me (albeit 1 or 2 years older). They yelled, a LOT, at everybody. That's what they do, it's what they're famous for. You have to see the humor in it. For example, the TI put his new Flight at attention (we had just gotten off the bus), then they said; "Lift up your right foot." Everybody lifted their right foot...Then they said; "Lift up you left foot." So everybody lifted their left foot...Next thing we heard at eardrum breaking volume was; "WHO TOLD YOU TO PUT YOUR RIGHT FOOT DOWN!" Then the TI, and his fellow TI's continued to holler at us for 10 minutes. Except for one moron that started jumping up and down, they told him that was REAL GOOD!, keep doing that until I tell you to stop. Their job is to make you uncomfortable, to make you try your best for their approval because getting screamed at isn't pleasant. They'll show you the stick first to get your attention, and slowly give you little encouragements as things go along. They're trying to teach you to follow commands instinctively to avoid the stick.
TI's back then, and I'll bet they still do, wear their sunglasses at night, inside, outside, daytime, in the rain, nearly always. I sometimes wondered if they wore them to bed. Upon graduation I asked one of the TI's why? I thought I knew, but I wanted to make sure. And sure enough he told me that they wear them because you can hide the expression on your face, but your eyes will always give you away. Often they will be smiling or laughing behind those glasses, or perhaps inside where it won't show. Try to understand that those leaders are human too. Even while they know why they do what they do, they see the humor in it too. They're just good at hiding it.
In a career with the military, you will yell at people to get their attention, you won't actually be angry, it's more along the lines of getting their attention and ensuring that they do what they're told. Learn that while you're going through it. Evaluate how you feel as you are getting the "stick," and how you and your mates are reacting. Think about how you might use the same tactics in the future. Everything you learn during that time you will use at some time or other. Appreciate the humor where you can, and learn as much as you can. You'll do just fine. GOOD LUCK!