The learning curve on 3d software is straight up. Honestly, I don’t think it’s worth it if your use of the software is limited to what you described.
I don’t do 3d work myself, but some of my long-term clients (both past and present) are 3d software companies. They’ve hired me for regular 2d promotional graphic design and software interface design, but in the process, I’ve learned something about the differences between the numerous 3d software packages, what each does, and who tends to use it.
AutoDesk’s Maya would be good, but it’s overkill in every way. In addition, it’s around $1500 per year.
Probably better and more focused for what you described would be AutoDesk’s 3ds Max, but it goes for around $1800 per year.
SolidWorks might come up, but it’s users tend to be industrial designers, which probably isn’t what you’re after. Besides, it’s around $4000
Rhinoceros 3D would work probably work for what you need, but it’s around $1000.
On the other end of the spectrum, there’s Blender, which is surprisingly good considering that it’s open-source, as in free-to-use. Of course, you’ll put hundreds of hours into learning it, so if time is money, it’s far from free.
Adobe Dimension might be a low-cost option too. It’s quite easy to use. However, that ease of use comes at the expense of options and capability. It’s rather limited in what it can do, but might be just what you need. I suggest looking into it.
There are lots of other 3d applications that are more geared toward areas you don’t need, such as CAD software, 3d animation, hobbyist model manipulation, and things like that.
Again, if you must do it, start out with the free or low-cost software. If you decide it’s not your thing, at least all you’ve spent is your time. As @PrintDriver suggested, consider hiring a contractor who specializes in 3d. Personally, I’d probably choose a different direction altogether, but I don’t know enough about what you’re trying to accomplish to really say.