Scientists Find Measles Likely To Become Endemic in the US Over Next 20 Years

Ask a physician, not the internet.
Andd I'd advice against visiting the US anytime soon if you're a foreigner.

It depends on how old you were when you were a kid and now. I would recommend getting your vaccination history and discussing it with your doctor. The vaccines do wane in effectiveness over time.

Well, don't visit unless you need to. And yes.

It's not very widespread so that risk is low - there's literally like 400 cases right now, in a nation of 340,000,000. But if you do happen to run across someone infectious, there's a pretty good chance of catching it. There's really no downside to getting a booster, so I'd say yes to the booster.

Something else to consider - and I don't know how the vaccines played out in your country - I've that in the US, everyone born in or before 1957 is presumed to be immune. Americans vaccinated between 1957 and ?1969? should get a booster because the vaccine the US was using at the time was less effective. And they're recommending that Americans vaccinated before 1990 consider getting a booster, because they had thought that one shot provided lifetime immunity, but it turns out that you needed a second shot as well. So if the vaccination program where you lived might have had one of those issues, you might consider a booster as well.