Reddit reviews The Art of the Native American Flute

A Native American flute would probably be a great place for you to start. Good ones are easy to play, and well-suited to experimenting and improvising, even if you don't know much about music. Totally appropriate for the porch, under a tree, etc.

The ones by Butch Hall are quite affordable--even some of his professional-quality "concert flutes" are within your price range. I'm a professional musician, and these are my Native American flutes of choice. They are also used by a number of recording artists. They aren't as visually ornate as some by other makers, but they have a beautiful sound, a sleek appearance, and a lovely cedar fragrance.

The "C, E, F-sharp," etc. refer to the "key" of the flute. Some keys are higher, and some are lower. A higher flute is smaller (and usually a little cheaper), and a lower one is larger. F-sharp seems to be a favorite among serious Native American flutists, but you can start with whichever appeals to you.

These flutes don't play as many notes as, say, a silver concert flute. That's not necessarily a bad thing, unless there are certain songs you want to play that need those other notes.

If you decide to go this route, you may also be interested in the R. Carlos Nakai book, which gives some background on the instrument and how to play it. Check out his recordings, too.