If you want to pay the renewal price, then it continues from the date the current one expired.
If you want to buy a new Sorcerer AP now for the full price, you’d have one year to activate it in 2025.
If you are worried they won’t be for sale, then buy the new voucher around one year from when you will go. This way, you have it and can activate it to began when you enter the park in 2025.