what new forms of entertainment were available to American people in 1920s

Answer 1

Radio! Most importantly, radio. Motion pictures became more widely available, and the phonograph became more popular, but both existed before 1920.

http://www.earlyradiohistory.us

http://www.www.thepeoplehistory.com/1920s.html

Answer 2

Also --
speakeasies
talking movies
http://xroads.virginia.edu/~ug00/3on1/movies/talkies.html