There are two important elements to decor that you have to take into account before all other considerations.
They are health and safety.
The '53 insanely clever' storage solutions (from the blog you are looking at) are not designs for homes with small children or toddlers or concrete walls, or people with little or no DIY skills, carpentry tools, or people who live in a rented home, even if your home didn't have mould and rising damp.
Some of the ideas are death traps for toddlers.
Some of them would be impossible for you to manage as your walls are concrete and you have already experienced difficulties drilling to hang a curtain rod.
At least 50 of them are completely irrelevant to your needs.
The three that are perhaps relevant are:
The plastic hooks in the back of the closet wall.
You could use those hooks in the kitchen on the back of your lower cupboard doors and keep your recycling bags hanging on the hooks.
The bed risers are nice if you have plastic storage boxes to slot under your bed.
Tension rods are a better idea than curtain rods for concrete walls if you have the window configuration to hold tension rods.
..........
The living room pictures you posted:
Blue couch photo - this room is not safe for small children.
- Those ladder bookshelves that lean on the wall are a disaster waiting to happen.
- Little breakable knick knacks - candles, tray, vase, etc. that children could break and hurt themselves with.
- The crates-as-furniture tend to look like junk in the average home.
- Couch looks comfortable and clean. Cushions are not neat but that it ok.
Red lamp photo -
- Tidy
- Clean
- Not cluttered.
- Lamp for light is nicer than just a ceiling light.
- Safe for small child and baby/toddler, as far as I can see.
- Fireplace clean and fire lit, seems to have fire guard.
- Comfortable furniture.
............
You mention your cords (TV, etc)
Are they spread around the floor right now?
If yes, this is a hazard for baby just learning to walk and for a small child too.
You absolutely need to corral them. There should not be any trip hazards on the floor.
Do the outlets in the room have childproof outlet covers? (This goes for all of the rooms).
.............
Wrt your kitchen:
Where do you keep your mop and bucket?
Broom and dustpan?
Are your cleaning sprays and liquids and powders (bleach, etc) kept in a cupboard that is locked or secured with childproof locks?
Where do you currently keep the toys?
You should have some sort of toy storage. This sort is the most practical:
www.target.com/p/toy-storage-primary-organizer-with-9-fabric-storage-bins-tot-tutors/-/A-53809419
(Sorry - link is for Target, a US store.)
Each bin could have a specific sort of toy in it - blocks, dollies, doll clothes, musical things, stuffed animals, train, cars and vehicles, dress up clothes, shape sorters/puzzles... They don't have to be jam packed.
Do you have that sort of toy?
Could you fit a small bookshelf unit into your living room to keep the children's books in?
Wrt your bathroom:
Are medicines kept in a cupboard that the girls can't reach?
Are items like razors kept up and out of their reach?
Same goes for nail polish remover and anything else that could be dangerous for the girls to get their hands on?
Do you have an airing cupboard for things like towels and sheets?
..............
A place where there is mould and damp isn't safe no matter how appropriately furnished, so you have to keep after the landlord/ council to fix it.