Help with problems

G_M

I doubt the council will care about the garage - it's not a habitable building.

Likewise the soil and grass - that's a compost heap - very environmentally friendly!

Seals on Windows all drafty and gas bill expensive Probably no requirement to improve, but you can buy window seals for £6 and fit yourself.

Big Hole in front room floor Hmmmm - that I would expect fixing! Do you mean in the carpet? In the floorboards? When you say 'hole' can you see down into the under-floor cavity?
Bathroom window wont open at all never has I'd expect that fixing especially if there's mould in the property
Black mold around sons bedroom window Cause? Does the room get ventilated? Do washed/damp clothes get hung on the radiator or on a clothes hanger in there?
Or is there a structural problem eg penetrating damp fro outside? (check for leaking gutters, or a broken downpipeon the outside wall
kitchen wall also goes black with mold

See above, but especially whether a window or fan is used when cooking. Is there a lot of boiling pans without lids (creates water vapour in the air)? Also check any drains outside the kitchen - blocked or broken?