Black mould around the window like this is usually caused by condensation. You can spend a couple of minutes in the morning wiping condensation away with a towel or piece of kitchen roll to help with this.
Black mould on the ceiling is usually down to cold spots in the loft. It could be because your insulation has been moved or disturbed which creates cold spots where moisture can form which can lead to black mould spots.
Damp on the walls
Damp patches like this could be caused by a number of different things such as problems with your roof, walls, chimney or drains.
Damp can sometimes be hidden by furniture or even kitchen cupboards. Keep an eye out for stains or discolouration on floors, walls, windows or even fabrics and carpets. It's also worth checking for a musty 'earthy' type odour too as it could be a sign of a damp problem.