Just unlock your wallet.
But the POS will start after 20000 blocks.
The unlock menu item is greyed-out, does that mean it's already unlocked?
Is unlocking the same as having an un-encrypted wallet? I never encrypted mine in the first place.
That's because I normally don't keep much coin on-hand, but now that I think about this, the POS will require me to keep the coin there.
Maybe I should look at a way to do the paper backup, just in case it's stolen?
It is already unlocked. You want to keep the wallet open so you can get your stake. You want to get your first year stake because you will get double of what you have now by the end of the first year.
Once the first year passes, it goes down to 2% stake.