I will actually go to the east part of the America as a study abroad, so I will feel personality of them. I am really looking forward to meeting American people though, I worry about weather I can make good relationship with them. So I posted this question.

You could break this up even more between East - West - Central - Southern and Midwestern Americans. It mostly gets divided by political beliefs. There's a few differences like the South is way more religious the most of the country and we refer to some of the area as the Bible Belt. Midwest and central our probably your most average american in my opinion East coast New England area (like NYC) people can be a little more aggressive, west coast everyone usually more friendly but you can get to some areas like Los Angeles where people can be a little self centered. Visiting though you'd never notice the difference how people are it's mostly just stereo types we have fore each part of the country. Cities and infrastructure would be the most noticeable. With the west coast being newer and more spread out then the Midwest and Eastern US that's much older and developed late 1800's early 1900's vs the west coast that didn't really blow up until the 1950's and 60's.