OK, here is my ignorance:

PeterT, where you ask do you want it for simple accompaniment to your singing, or do you want to play melodies? I didn't know these were different things. I guess, both? Accompany when singing and be able to play melodies for the instrumental parts? The trick is say I want to sing The Piper Who Played Before Moses - well, what do I do after singing "And this is the tune that came out" when the wild music plays?

And when you ask Are you after a primarily chordal or linear music environment? I don't have a clue what you're talking about. I think I think linear, since that is why the piano makes sense to me...? But not at all sure I'm grokking the fullness of the jargon here.

And when you say In most folk songs and ballads, you can sing them strumming a guitar with chords after about half an hour of work, that would be a great start. Can I do that with an autoharp too? - Also, it may be overdone, but I'm not doing it for anyone else, really, for now. I haven't even had the courage to sing in front of anyone who isn't a relative or a fellow 'catter, and I do believe I can sing, now!