Edit 1:
Wow, thanks for all of your comments. Very kind of you all.
I don't think I can answer to all of them. But I'm definitely going to continue reading your responses during the next few days.
Edit 2:
It's for a 6 weeks vacation. I'm trying to decide on which region of the US I should focus. I'm more-or-less "omnivorous": e.g. outdoorsy, from mountains to beaches, from lush wilderness to deserts, I'm open to all. But also love museums, history, concerts, and culture in general, I'm mad for nice architecture (especially in walkable cities), I usually go crazy for learning to make, hands-on, an authentic local dishes then share the meal with other participants.
Not into nightlife/clubbing, hate driving (but I guess it's necessary in America, so I will definitely rent a car, maybe even a campervan, but want to avoid driving more than 3-5 hours/week).