I’m leaving for the US (Houston, Texas) with my father next week for cancer treatment (I am the patient). Don’t know how long the stay is going to be. To keep optimistic I like thinking about doing fun things - motivates me to think I have to be well in order to do them.
You should be asking for Houston things, not American. Though you can fly to other cities, but the US is big. Texas is 695,660 km2, France is 543,941. Different states do have very different cultures - even in Texas you will find several different cultures. You cannot do it all, and I suspect your treatment will limit how far you can travel. Fortunately Houston is a big city with plenty to do and the public transit isn’t impossible to use. search for your city and tour and you will find plenty of interesting things - https://www.visithoustontexas.com/ is what I came up with though I don’t know if it is good.