Judaism is constituted of the acceptance and practice of the mitzvot. Thus, it is inconceivable that a non-Jew could enter the nation of Israel and acquire kedushat Yisrael without acceptance of the yoke of mitzvot. There is no Judaism without mitzvot. However, there have been different halakhic positions over the centuries as to whether or not the acceptance of mitzvot requires the complete and perfect knowledge and practice of the mitzvot at the time of conversion, like circumcision and immersion in the mikvah.
Yehiel E. Poupko, “Making Jews: Conversion and Mitzvot”, Sh’ma (March 2011), 13.