In addition to what
@Bonsai Nut
is saying.
While there ARE large.. bonsai trees... quite large in some cases...
The methods in which you train a bonsai tree, are essentially MINIATURIZED versions of that same tree... full-sized, exposed to all sorta of natural events that age, shape and mature a tree... the trees that STAND out of the 100's of Thousands that you see....
Miniaturized, Ancient nature...
The INTENT and attention to scale and taper is partially what creates this. It's the work you put IN...
You'll see soon enough, I'm sure.
On the plus side.. you have some DECENT (said like Bubbles) material to begin with, If I'm being honest.
Soak up some Youtube videos
Just search "Bonsai from Nursery Stock"... look for some of the species you have...
I STRONGLY recommend checking out the "Growing Bonsai by Jelle" channel. SUPER informative and entertaining.
Peruse the threads... search "Nursery Stock".
Keep us posted..