As you continue to sleep, it feels like you're beamed more information about the next world, so that you can better adjust.
Humans in the world you're going to have the ability to change their biological sex purely through thought. If someone wants to, they can become the other sex, just by willing their body to change.
For a man to become a woman or a woman to become a man it takes about seven months, the process is a bit painful, and the resulting body will be skinny and weak at first due to the transformation consuming so many callories. However, much subtle transformations are possible.
People may choose to keep their bodies in-between male or female, and/or keep their genitals in-between male and female. They also may choose to have neither set of genitals and/or bodies with neither sex's characteristics. People may also have genitals that don't match their bodies of course. These transformations take less time if they're less drastic. People's presentation often varies, but usually they're always thought if as the sex if their body not their genitals.
You wake up. Wondering what this world's version of you chose to be, ready to inspect your new form.