I guess they're both 'my own country', but one thing of the very few things I think the UK could do with importing from the US is better practical adult education.
Like, yes, the US university system is all fucked up to get the most money, but the range of options here for hands-on learning as an adult compared to US community colleges and similar I knew irritates me a bit at times. There is so much talk in retraining people and having a flexible workforce with lifelong learning, but even in a city with what is meant to have good colleges for that, there ain't much in comparison to the Midwestern town I was in and those classes are not surpisingly tend to book up quickly.
And really, practical education in general. Both high schools I went to in the States have classes that are basically 'first house care' that goes through a lot of practical DIY and needs for maintaining a house. My local college here has a short course for basic plumbing and one for carpentry, but really, the options to learn about that sort of thing practically, hands-on with knowledgeable people, just seems so thin. Likely other parts of the UK are better at this, but from people I've talked to, it's just this attitude that that's how it is.
On the flip of that, the US needs to import a fuckton - lobby groups attached to US tax preparation companies has blocked repeatedly mostly healthcare and a simpler tax system ( and that pisses me off something fierce).
I've always imagined US trains to be amazing
Sadly no, the car industry got in there so a lot of train lines in the US are pretty much freight only & there is far less support for traveling by train to the point that there are several states you can't get to by train. There has been push back against that, but for all the issues with lobby groups in the UK, the US ones are terrible.
In the UK you dare not fly a flag because its might upset some minorities. British people shuffle out awkwardly rather than stand for the anthem.
Maybe you need to live in a different part of the UK. There are several British flags flown around me and 'Lest we Forget' garden artworks in the streets around me, but then I live a 10 minute walk from a veteran's pub - many of those veterans being 'ethnic minorities' too as not much farther along are the Sikh temple and mosque.
And oddly enough, where I lived in the US, there was a couple people who flew the British flag - not sure if they were connected to the local air base or the universities or what, but flags are just a thing in some parts of the US and some parts it isn't.