Help on whether or not I should make a shared AmEx Gold my own?

Hello r/CreditCards! Please forgive me for I am still relatively new to this.

I (28) was graciously given my first credit card, an AmEx Gold card, when I was 17 as a “gift” by my dad for graduating high school. It was mainly given to me to help be build a credit history at an early age. It was also one of those “use ONLY in case of emergency” cards made me, regrettably, flex the definition of the word ‘emergency’ in my earlier years, but that’s neither here nor there (and i’ve paid him back all the money, lol). and I have otherwise not used the card in years. As far as I know, the card has been in my name the whole time, but I believe it only makes me an authorized user/allows me to access my dad’s credit line. It shows up on my CreditKarma report along with how long my card has been open (not the credit line itself, just my card) but I have no idea what the credit line actually is.

Anyway, more than 11 years and 7 credit cards later (FULLY under my name, lol) , I am currently in a financial situation in my life where I have considered taking full ownership of the card. I have also consulted my dad about this, who contacted AmEx support on the issue who also says that – before undergoing any credit checks – I should be “able”to make the card my own. The question here is, should I?

I’m having trouble finding resources online regarding a situation like this, and am unsure of the ramifications that may come from it all. Would I essentially be ending access to my dad’s credit line and creating my own credit line? And how would that affect my credit history? I should add that I am financially stable enough to handle the annual fees with this card and have been interested in opening an AmEx card for a while now. My second oldest card is also slightly younger than this AmEx gold (June 2014, vs April 2014 for my AmEx) so I would still have history established. I just want to make sure I have the right things considered in this decision. The card is still open but has not been used in years (still tied to my dad’s line which is used regularly, which is probably why it has not closed).

Any and all help would be appreciated, and I’m happy to answer any additional questions! Ty in advance 🙂