I regularly use Inventor to draft shows in scale from large automation heavy musicals to much smaller, college scale, shows. I've been drafting in Inventor primarily for the past 5+ years.
On to resources on learning it, Youtube is a great resource for finding help with specific things. The tutorials from Autodesk are also very good. They are built into the software and installed when you install the software. If you have money for an online class I have good experience with Globaletraining.
http://www.globaletraining.ca/etraining-courses/product/autodesk-inventor-2018-guided/
The class is expensive, but it is worth it in my opinion. I have used a similar class to train a draftsperson in drafting for
theatre from minimal
CAD experience very successfully. The one thing most tutorials or classes don't
cover is a tool called the Frame Generator. It is my most used tool because it can frame a
flat or a
platform in a matter of minutes when properly set up and used.
As to what people have said about making a bunch of parts and then assembling them, that is one workflow possible in Inventor. That is called "Bottom up" modelling. It means you start at the bottom, the parts, and work your way up to the top, the assembly of all the parts. That is just one strategy of many on how to model in Inventor. Autodesk has an article on the different workflows possible. Here is a link to a brief description of them:
https://knowledge.autodesk.com/sear...63FA128E-63E2-4176-8653-327BD80D8A43-htm.html
I personally do a mix of them, changing workflows to use whatever fits the situation best. I could probably do a several hour long lecture on the pros and cons of AutoCAD vs Inventor for drafting in theater, as I've had that debate myself with co-workers and myself for many many years but I digress....
Anyone can feel free to
send me a PM or anything if you have any specific questions or want opinions from someone who uses Inventor regularly for theater.