The US is a huge country? What city or state are you going to?
There are zillions of good places ... all thousands of miles apart.
Empire State Building, Ellis Island, Central Park, Times Square ... if you're talking about New York City .. New York State is another story.
Statue of Liberty NY , New Orleans, Niagara Falls, Any National Park, Hoover Dam, Grand Canyon, The Rocky/ Smokey Mountains. Washington monument, Biltmore House.. Just to name a few. There's also Hooters Restaurant/bar .! and many Museums as well Have fun.
The mountains in Colorado. Hike. The beaches around the Florida Keys and Hawaii. If you like desserts, there is the Mojave in Southern California and New Mexico. If you like forests, the Appalachian Trail is nice. Civil War battlefields can be fun for those interested in conflict.
You're going America. What does that mean?
NYC and Los Angeles
Well, since you don't say what part I would say, I like the big cities like San Diego, Seattle, or San Francisco on the West Coast or New York, Boston, or perhaps Washington, D.C. There is always so much to do and see, great restaurants, sites, and the like.
Minnesota, the Dakotas & Wyomin
Canada. And i hear Mexico is a ball.