There is a book by Chaim Donnin “To Be A Jew”

In it he goes through the various Mitzvos.

But think about it – imagine you meet a Jew that never heard of Judaism – what does it practically mean if you want this person to be a Jew?

The answer may surprise you, for the truth is, if the person begins to observe all the commandments, you have not “made a Jew,” rather, a person who does a bunch of rituals.

To be a Jew, first and foremost means to believe in the Jewish belief system, namely, there is a God who is infinite, who desired to dwell in this realm, within us, as he loves us, and for this reason, he gave us Mitzvos, methods: like a hug, of connecting to him!