I recently discovered that I am a descendant of the Sephardic Jews

I recently discovered that I am a descendant of the Sephardic Jews who colonized Brazil. I am truly happy and have some questions.

1. Where can I find official information about Jewish family trees?

2. Is there any institution that keeps this data, like FamilySearch?

3. Is there any scientifically valid way to link someone’s ancestry to their patriarchs? I managed to find Jewish lineages that go from my grandparents to the patriarchs on FamilySearch, but I don’t know which lineage is the most reliable.

4. Is there historical data on the genealogy of ‘Branca Dias Coronel’? A historian traced our family tree back to Branca Dias, a Sephardic Jew who was persecuted by Portugal.

My grandfather descends from her, and I later discovered that my grandmother does too. I have the surname “Oliveira,” common among Jews who fled Portugal. In short, I have a lot to learn and I’m excited!