With no 3D in Photoshop what should we use?

Best or easiest are not necessarily the same. It also depends what you want to do.

If you want to create your own models and are looking for photorealistic renders then you should look at full 3D applications. All will require some investment in time to learn, but the principals are similar between them. You could start with Blender 3D which is free, but regardless of that is a very capable 3D application. There are thousands of online tutorials in Blender, that will give you the grounding in the 3D processes from which you could decide to stay with Blender or move on to another paid application, or integrate Blender into a workflow with other applications.

If you only want to add labels/decals to premade models, then Adobe's Stager is designed to create scenes by adding materials and decals to existing models. It comes as part of Adobe's 3D Collection which requires a separate subscription to CC.

Dave

@justinatTVS 

Do you have Creative Cloud or the Photography plan?

• One choice is Adobe Illustrator — they have revamped their 3D in addition to keeping their legacy 3D
• Many people use Blender, which is free

I'll tag our 3D expert @davescm , as he is likely to have other thoughts.

Jane