Hey @oldenminah_, welcome to the community.
Hope you’re doing great!
I would recommend you cancel your subscription on your old account to avoid any further charges, and you can sign up for Premium on your new account: https://www.spotify.com/premium
I would also close your account if you no longer need it: https://support.spotify.com/account_payment_help/account_help/close-account/.
Hope this helps 😊