They have very different working principles and methods. Fusion 360 focuses on 3D modeling and manufacturing, while AutoCAD has its roots in 2D modeling

My product is 3d I think I want to do it in fusion 360 software would do it.

Of course, your Product is 3d so you can use fusion 360 software 

You can use F360 for free, so there's really no reason to not try it.

I really like Fusion. A lot.
I can't speak to how hard it is. Pick a simple project and give it a try.

Brother its not a hard software, its very easy software

I use Inventor full time at work, but like Fusion 360 more for my home projects (cosplay, 3D printing) the modeling environment is more user-friendly I find.

There are a lot of options out there based on the type of modelling you're doing (Rhino, Blender, etc.).

If you're adept at Inventor you won't have any trouble learning Fusion.