Piers Anthony's reputation for awfulness is overstated but not strictly incorrect, in my opinion, though most of my problem with him was repetitiveness - his male characters in particular are basically all the same dude, and not even a particularly interesting dude. If you stay away from the Xanth stuff and give up as soon as you start getting bored you'll do okay, though; I remember the Apprentice Adept series fondly, and iirc the Incarnations of Immortality was very well received but I remember it as being more work to get through.
LeGuin is probably too complicated. I have a friend who's a big fan of hers who might be able to recommend a few books on the simpler side, though.
On that note, Octavia Butler: Fledgling fits the bill pretty well (and is another favorite), the Parable books are almost certainly too dark but otherwise a good read, I haven't read the rest of her stuff. ETA: Fledgling does come with a TW for underaged/mixed-age sex; the specific situation is decent consent-wise (it's a fantasy book) but if you're uncomfortable with that you probably still want to skip it - no graphic descriptions but it's pretty blunt about what's going on.
My LeGuin fan friend also recommends James Tiptree Jr as a similar author, but I haven't gotten around to reading any of their stuff yet.