3D software

For game development specifically, Maya, 3D Studio Max, ZBrush, Blender, Substance Painter, Substance Designer, Houdini can be used frequently at different studios.

General 3D software also includes 3DCoat, Modo, Cinema4D, Fusion 360, Marvelous Designer, Mudbox, Sketchup, Rhino, etc. Some software is better suited for certain work so it helps to learn multiple software for your skillset.

Blender is free and fairly easy to use once you get familiar with it, Cinema 4D is also fairly easy but I prefer Blender over C4D just because I'm more used to it, I think the largest problem that comes is not the software but finding what you want to actually make, or maybe it's just me.

Blender is great though for just about everything though in summary

Blender for sure. Its free which is awesome, super extensible, and you cant imagine the number of tutorials out there on YouTube and elsewhere

question: is there a section on turbosquid leaks or other 3d model pages?

I would recommend blender. There are tons of tutorials about blender on youtube! =)