33 (F) finally trying to figure out how these shares my parents were custodians on work.

So, I have a handful of different shares that my parents got for me and I’m finally trying to make it easier for me to manage. Before I would just wait for the tax documents and check the statements and be done with. But I don’t live with them any longer and it’s a pain to get them from my mother. I went to go add one to an online account and they said they had to mail me an online access code. So I called to finally change my address and now they say I have to fill out all this paperwork with my dad to do that. isn’t the point of this the fact that I turned 21 it was now mine?