Finding contacts from my old Tracfone

I have a question for anyone who may be more tech savvy than I. I have an olf LG Rebel tracfone that had issues with the charging port so I ended up getting a new phone on a different provider. Anyway, I lost a lot of contacts from that old phone that i’ve been trying to retrieve. I ordered a sim reader and will install the software to try to find those old numbers off of the phone. That will probably only work if they were saved to the sim. When i try to start the phone I get LG authentification error 9. My question is, If i reactivate the old tracfone with a new phone number, should I be able lose the authentification error, and to access those old contacts if they were saved to the phone’s hardware?