The culture, customs, and habits tend to vary depending on which region of America you're in. The west coast is different than the east coast, rural towns in the southern U.S. are much different than in cities like New York, Chicago, and Los Angeles. Apart from actually living in the U.S., I would recommend talking with Americans from different areas of the U.S., watching tv shows and movies that are current, or holiday movies if you're curious about that aspect of U.S. culture, read books (modern literature), search for Youtube videos of non-Americans' reactions and stories about visiting/living in the U.S. Hope this helps! :')