>I guess I am struggling to see on what basis one would do anything (except perhaps the immediately gratifying) if one had no desires about future states of the world.

It's not that you can't work towards an aim, but just detach yourself from the expectation of outcomes. It's ok to want to become rich, so that you can help your near and dear ones, and work hard towards it. But always be aware that the outcome of your effort need not be plentiful always.

>Unlike Arjuna I can’t just ask a god what I should do!

You can read the Bhagvad Gita.