You want mundane differences?
In England, when disconnecting an electrical item from the wall, we would say we ‘unplug’ it. In Ireland they say ‘plug out’. Yet for the reverse, both countries say ‘plug in’.
Broad generalisation but generally true: in the UK, the Indian restaurants are great but most Chinese food isn’t all that good, except as cheap takeaway rubbish. In the US, it’s the other way around.
In England, post gets delivered on every day except Sunday. In Sweden, there’s no delivery on Saturday or Sunday.
In Italy, if you want to buy a bus ticket you (usually) have to go to the nearest tobacconist. English people find this a bit weird, because we can’t see any link between selling tobacco and bus tickets. But Italians visiting England think it’s weird that if we want to take a (pre-digital era) camera film somewhere to have it developed, we go to a chemist (pharmacy). They go to… a photographic store. They can’t see any link between a chemist and photographic services.
US: town planners understand that where there are shops and theatres and suchlike, people will need places to park their cars. Here in the UK, there are countless shops and malls that are rendered impossible to reach by car, because of all the no parking / no stopping zones and similar restrictions, all enforced with draconian zeal. There are also businesses that simply have to give up because there is nowhere for potential customers to park, for miles and miles around.
Mixer taps. Almost ubiquitous in Sweden and the rest of Scandinavia. Almost unheard of in the UK, at least until a few years ago. Now the idea that they make good sense is slowly gaining acceptance.
In Indonesia, a ‘shower’ is almost always just one tap, for cold water. Europeans expect a hot tap as well. This sounds daft to Indonesians. They understand you might want to take a shower to cool down, but that’s all.
Place where you go to buy bottles of beer to drink at home. UK: off licence or ‘offie’. US: liquor store. Australia: bottle shop. Sweden: all owned by the state.
Chewing gum. Banned in Singapore. It’s an illegal substance.
And there’s plenty more where those came from. But it’s late and I’m tired.