I think a good way to think of these software packages is to break them down into categories:
Parametric CAD: Solidworks, Inventor, CREO and the enterprise grade Catia and Siemens NX.
Explicit Surface Modelers: Rhino and Alias would be the two biggest players.
Renderers: Keyshot, Maxwell, Octane, Vray maybe to a certain extent Blender
The popularity of the different packages varies by location and industry. The good thing is that learning one of the tools in each category will allow you to learn the others quickly. Most companies looking for a designer rather than a CAD monkey won’t care a whole lot which tool you master.
For most product design needs in consumer products, Solidworks is very popular for the CAD work. Detailed surfacing work is a bit of a specialty but Rhino is quite popular for this. But honestly, as someone who’s been using Rhino full time for the past 2 years, it’s about as fun as removing glass shards from your eyes. Also, the future of detailed surfacing work may be changing in the very near future. I wouldn’t be surprised to see the need for dedicated surfacing tools to be greatly diminished as better surfacing tools get integrated into CAD packages. For example, Autodesk’s Fusion 360 which is a hybrid between a CAD and a surfacing tool and makes for nice workflow.
Lastly, for rendering, it’s hard to go wrong with Keyshot. It’s simple and intuitive which makes it great to learn the basic concepts of rendering. While it may be lacking some of the very advanced nitty gritty details, it’s so fast to get great results from Keyshot that it’s a bit of an industry staple. My biggest suggestion when learning rendering would be to dabble in product photography. It’s way more intuitive to learn how to light an object by moving lights and modifiers around a space than moving around little sliders and waiting for the results to show up.
Lastly, I’d also recommend learning the crap out of Photoshop. Not only for sketching but also doing the post production of pictures and renders. It’s a vast and somewhat intimidating program but if you can wield it, you can save a lot of time and bring your results to a higher level.
TL;DR I’d start by learning Solidworks and rendering in Keyshot and doing your post production in Photoshop. If you eventually see a need for it, have a look at the advanced surfacing options that suit your needs and industry.