Me what times would it e and where do i put a x to show where london will be in 12 hours time

Look at the picture I attached.  It's a part of your sheet,
with some added information.

-- The line between the day-side and night-side of the Earth is the line
where day changes to night, or night changes to day.  Even if we don't know
which way the Earth is turning in the picture,  London is halfway between
sunrise and sunset, so it's about Midnight there.

-- Do you remember that the Earth spins all the way around in 24 hours,
and half-way around in 12 hours ?
So in 12 hours from now, London will be halfway around, on the day side,
and it will be about Noon there,

When you see where I placed London at Noon on my drawing, you may
wonder why it's so 'high up' on that side.

Remember that the Earth is not spinning arounf the sunrise/sunset line.
It's spinning around the 'axis' ... the line through the north and south poles.

This is a picture of the Earth during the dead of Winter in the northern hemisphere.
The north pole is tipped away from the sun. You can see that London spends
much more than half of each spin in the dark, and much less than half of it in
the light.  This corresponds to the short days and long nights of Winter.