Wow - there have certainly been a lot of sweeping generalizations about the US on this thread! The United Kingdom is just over half as big as California. And there's a huge amount of country to the east of California. I'm certain you would hate if people assumed everyone in the United Kingdom behaved exactly the same and thought exactly the same and lived exactly the same - but so many people (not all, but many) on this thread are acting as if Americans and all of America are identical. I've lived in California, Oregon, Nevada, Pennsylvania and Georgia - in big cities and small towns. I currently live in Idaho. They're all completely different from each other. Cost of living, schools, extracurricular activities, diversity or lack of the same, driving skills or lack of the same, food (and yes, we do import fruit and veggies - I'm not sure why someone up thread thought we don't), religious beliefs, and on and on and on.
Except for the non-stop negative news coverage, Trump has not really affected my day to day life. And I rarely notice guns even in red-state Idaho - although I can't say never. If you are living in a larger city, there is definitely good public transportation. I would say that holds true especially in the northeast. But we do love our cars - and they are indispensable in the bigger western states.
One generalization I have found to be true is that Americans are friendly and open for the most part. If you do decide to move here, I think you'll find people to be approachable and helpful. (Of course, not having lived in Massachusetts, I can't guarantee that! My couple of trips to Boston haven't led me to believe otherwise, though.) I've been to all 50 states and while I might not want to live in most of them (mostly because of weather issues!), I have enjoyed the people I have met. Just like I have enjoyed the people I have met in other countries, lest you think I am one of those Americans who "never travel".