It's not your mistake.
Type on Path does not work on compound paths. Hence the warning message.
Clearly, I'm a rookie! What is confounding me is that the message seems to transfer to further attempts to practice in spite of my closing without saving. I assumed that if I did this any past set-up, or file, I might be working on would be erased. But it seems to follow me and thwart any attempts to successfully carry on. How might I "get out of" compound paths.
I assumed, perhaps incorrectly, that compound paths means I'm attempting to work one project over another, and that they are conflicting. Is this correct? Any help would be greatly appreciated. Thanks.
A Compound Path is a combination or two or more paths, usually (but not necessarily) with what appears to be one or more holes, such as the counter in an O.
You may uncompound them by Object>Compound Path>Release, but then you lose the hole(s).
There are ways of getting round the limitation.
What to do in your case depends on what your case is.
Could you post a screenshot of the troublesome Compound Path (you may click the icon that looks like a camera, or post something on a website and provide a link)?
You might want to practice al little. Open a new file and just draw a path with the Pen tool. Click and hold with the mouse on the Text tool to reveal other options. The Type on a Path tool is the third one down. Select it and then click on the path you just drew. Start typing your text. It seems as though you are using some odd construct as a path for your type.