For now I can say, if you're serious about 3D, you'll need to learn a lot of Analytic Geometry. As for what your dad said, no, 3D does not mean 3rd integrals, 3D means 3 dimensions, period (no offense meant by this). You need analytic geometry to learn how to project 3d stuff on a 2d screen, how to decide whether things intersect, and how to draw them. Integrals could be used for some stuff I guess, but in games are mostly used for physics, and not much else.
"3D tutorials are BS because they use really complex math and I can't understand it. Wikipedia uses really complex formulas and equations for really simple things."
Representing a 3d world is not a very simple thing, as things can be rotated, scaled, translated, amongst other things. That "really complex math" you mention, isn't in fact all that complex, but as I've said before, you need to know AG. I suggest you grab a book on the subject, or on Computer Graphics to learn specially about how to define a coordinate space, and how to operate on it. It's not very complex once you get used to it, it simply comes down to multiplying matrices, if you do it right.
- Vectors and operations (normalizing, dot- and cross- product)
- How to convert from a space to another
- Homogeneous coordinate (z for 2d, w for 3d)
It's really late and I'm brain dead, if I have time (which I probably won't), I'll look into this on the weekend.