I am not an expert or anything but I have a little insight into how one might find out f they are descended from a Cohanim . Sometimes an engraving on gravestone can let family know that a Cohanim or a Levite is buried there. A hand with fingers split in the middle like the Vulcan sign from Star Trek is common for Cohanim 🖖🏼 and a pitcher of water is common for a Levite.
The finger split is an genetic inherited trait that can only be performed by someone that has a Cohanim ancestor. My father was a Cohanim and I can do this with my fingers. My sons can do it also, inheriting this trait from me and their maternal grandfather. But their own father is an Israelite so my sons are not considered Cohanim. This special trait of splitting fingers can’t be be preformed by their father. So if you can’t split your fingers, you can infer that you are not descended from Cohanim but if you can, it doesn’t mean your are one because you could have inherited that genetic trait from your mother but not the Cohanim designation.
My father as Cohanim was often called to bless a congregation and he would hold out both hands with his fingers split and recite the priestly blessing.
Also getting back to grave stones, after my father’s and grandfathers names written in Hebrew it says Ha Cohan. Other family members have Ha Levite in Hebrew written after their names. By the way, my grandfather’s last name was BROK which I always assumed was a translation of Baruch or blessed. The family later changed it to Brooks in NY. My grandfather was from what is now GOLUB-DOBRZYN which now is in POLAND but was part of PRUSSIA and RUSSIA
Fredrica Brooks SeLss Researching BROK and OSHEYACK from GOLUB-DOBRZYN, POLAND (PRUSSIA) SCHNUR from TARNOW, POLAND(AUSTRIA) STARK from KOTAJ, HUNGARY, HERMAN from FEHERYARMAT, HUNGARY and TREBIES from SATU MARE, ROMANIA ( HUNGARY) SRULOWITZ and SCHWARTZ from KEMENETS PODOLSKY, UKRAINE (RUSSIA) and ROMANOFSKY from KOPYS, MOGILEV, BELARUS (RUSSIA) and SCHWEITZER from MOGILEV, BELARUS by way of GLASGOW, SCOTLAND