Contractor Question
You are in a strange little niche which doesn't have a clear path forward. you are small enough that a full powered design system may be too much, but also you don't want to undercut your potential and you may need a lower powered tool to help you past the skill gap but not limit you with its capabilities.
There are lots of things to consider about the tools you can use. My guess is that cost will be part of your considerations as well as ease of use and ultimately the end product. While considering cost, you need to find out what type of license the tool you are looking into has. Licenses can be subscription or perpetual which may impact how you intend to pay for them. Also Some of the tools out there are just meant for modeling while others are both capable of modeling and drafting. Drafting being the creation of your 11X17s.
The good news is that you are used to thinking in a 3D design mind set, the hold up is that its not always easy getting over the learning curve of some of the tools.
AutoCAD will 100% be able to get done what you need. It will take a commitment to learn the program. It can be done in evening sessions, but if you could find a crash course it would probably be easier. While the cost is not to bad, some people think its expensive for small business. If you build in the cost into your projects, its pretty cheap. There is AutoCAD LT which is cheaper, but it cannot do 3D (no renderings). There is flex licensing which would may help with cost. At the end of the day though AutoCAD would do exactly what you need! Once you understand some of the basics its not hard. AutoCAD can handle both modeling and rendering and drafting. I would recommend getting AutoCAD if you have the time to invest in learning.
If you need low cost/no cost and fast you can check out Tinkercad. You can literally have a design within an hour. That said the purpose of Tinker CAD is not necessarily your industry. If you are just wanting to get your feet wet and play with some concepts, the cost of this one makes it worth at least setting up an account and playing. I have used tinker CAD to build some home projects and it worked well. That said you wont get standard drawings as part of your output. It cant do drafting in the normal sense of the word. You can however take screen shots and drop them in something else. If you are wanting a little more high power rendering you can export Tinkercad designs into other applications. If you are wanting to stay with the "free" route, you can dump them in Blender. That said rendering in blender would require a learning curve. (example of some of your types of projects ex1, ex2, ex3) I really like tinker cad but you may end up hitting limitations in capabilities sooner than you would like.
Another option that you may want to consider is Fusion 360. While its purpose is not necessarily for your types of projects, it is useful for wood working projects for things like furniture. It can definitely do the design you need and do them well. There are licensing options for startups as well. Rendering is fusion looks fantastic and is easy once you have your design set up well. If i'm going photo realistic and want to do it quick i go with fusion.
These are just some Autodesk products, there are some created by providers but they all tend to have similar benefits and limitations. You may find Sketchup and Bricsys Shape as good options as well.
Three are also things like Revit which are a fantastic tool but may be too much horsepower for the size of projects you are looking at. This is not to say that AutoCAD and Fusion arent powerful but that the scope of your projects are may not dictate the use of something like Revit.
If i were you, i would start with tinker cad just to get you into the the design world now. Its very low commitment. If you find you like working with a modeling software (like tinker cad) i would the look into Fusion 360. If you find your self wanting the ability to drawing things (using 4 lines to represent a 2x4 ) as opposed to model things I would go look into AutoCAD. Most of these applications have a free trial so you can go test them all.
CADnoob
