Joint Bank Account Theft

Burner account. This happened in Florida, U.S.

When I was in high school, my dad and I and opened up a joint account at a local bank that my family had used for a long time. Throughout high school and for some years after, my dad would deposit large sums of money (5 digits) into the account and tell me to not touch it because he was “moving money around.” I never questioned any of it, but I did find it weird. I was 17 for the first year of this happening, but turned 18 while it was still happening.

I was recently tipped off by my sibling that the money that was going through my account was likely money (either cash or proceeds from stock sales) that was left to me by deceased relatives on my dad’s side of the family and that he used the shared account to deposit money in my name and withdraw it into his own name. I have requested some old bank statements from the bank, but these deposits only say “deposit $xx,xxx,” so they’re not very informative.

I am seeking legal advice on how to navigate this in a way that lets me discover whether or not there was money stolen. Would I have to hire a lawyer and/or PI? Would the bank have more detailed information about the deposits that would tell me where the money came from? Would the deposits that occurred before I was 18 be legal since I was a minor and a dependent of my dad? Any advice is appreciated. Thanks in advance!