I think of the Use Year like a fiscal year.
If I had an October Use Year, the year runs from October 1, 2022 (when the points were received) until September 30, 2023.
If you do decide to rent out points:
If you use David's, you tell them about the points you want to rent out. They find you someone who wants to use those points.
If you use the
DVC Rental Store, you can do it the same way. But you also can set up an account with them, not tell them about your particular points, and look at their list of reservations that people want. If you see a reservation that you want to book, you use the website to notify them, and they will get you the particulars.
The timing works the same way as if you wanted to use the points yourself. If you wait until August to start thinking about using points that expire at the end of September, there might not be any availability for which you can use your points.
With both, you also can make a reservation yourself and have them try to find someone who wants it.