Umm... some shower thoughts
A somewhat clumsy, geeky wallflower is kind of unhappy with her life and tries to find her own self, visiting an old (forgotten?) mountain spring. In hope of a mental rebirth, she could take a naked bath in the cold water, diving down to be completely surrounded by water. When she walks out of the water, everything looks more colorful and brighter, and a scent of fresh air reaches her nostrils. She feels just great before she realizes that her clothes are gone.
In the same moment, she hears male voices. She hastily gets behind a bush to hide her nudity. "She can't be far away."
Then a couple of strange clothed, armored men reach the mountain spring. "She went into the water," one of them says. "Hopefully, she didn't drown herself!" a small man giggles, "When have you ever the chance to have fun with a princess?", "Her last meal before she goes to the gibbet...," another man laughs.
The men could further examine the spring and then disappear after diving into the water or they could walk away to search the woman.
(She could try now or later to get back home through the spring.)
She could realize that she wears a necklace with a seal ring but doesn't wear her own silver necklace and her ear studs anymore (and other jewelry).
Her body could also be different. The body of the princess. A beautiful princess. But a princess on the run.
That way, a lot would be new for her: the world, the sensations of her new body, the attention of men, the fear of being caught, ...
She would need to find out, why this happened and why she (the princess) is on the run. After finding out, she could try to restore her life as the princess she was never born into.
Well, there are so many things which would qualify as long-term objectives, without being quite dominant in the beginning. For later it may be useful to have something that drives the story. You don't need to have every detail for that, though it should be clear enough to be able to keep things logical when you make the details known.
In the above example, the objectives could be to really find herself, find out how to get back in her own world, find out about her new body, find out about why she is on the run and what happened to her "family", maybe revenge her family, restore their status and be the princess...
I personally dislike collection stories for several reasons.