On December 3, 1980, Yoko gave a detailed interview to Peter Ochiogrosso for Soho magazine that covered her arts career before she met John Lennon. Below I compare its contents with other sources I have obtained on Yoko.
In the article, Yoko first reveals that she chose men who were openly "insecure" because they were the opposite of her father, who presented himself as flawless and cold. Her dad was a Tokyo banker who was transferred first to San Francisco in 1933 (a month before Yoko's birth) and then to New York. Yoko and her mother joined him in 1935 and again in 1939-40. The family left the USA in 1940-41 due to impending war and her father's new job in Hanoi. They returned to New York in 1952 and Yoko enrolled to do art and music at Sarah Lawrence. She married Toshi Ichiyanagi (then known as Tossi) in 1957 and embarked with him on pursuits in the avant garde. In 1959, they moved to 112 Chambers Street where she eventually curated concerts influenced by John Cage and attended by La Monte Young and his circle. Yoko had an affair with Fluxus founder George Maciunas at this time and dedicated poems to him.Yoko's first musical performance was "Grapefruit in the World of Park" at Village Gate in 1961 She also performed it at the Carnegie Recital Hall on November 24, 1961. Yoko complains to Ochiogrosso that the New York Times cut her out of its report of the concert.

Yoko also did origami demonstrations, as shown in this photo from early 1962:
In 1962, Yoko went to Japan to perform at the Sogetsu Arts Centre with John Cage, David Tudor, Toshi Ichiyanagi, Kenji Kobayashi and Toshiro Mayuzumi, resulting in this photo:

Yoko stayed in Japan and, at some point in the following twelve months, she apparently had a breakdown, took an overdose and was admitted to hospital, where she met second husband Tony Cox. It was while with Cox that she would move to London in 1966 and bump into one John Winston Lennon.