First - an 8GB phone wasn't usable in 2017, unless you were just using what was on it.
Second, the card is probably corrupt. You can buy a new one for just over $7 from
Amazon. (I wouldn't put anything but a SanDisk in an old phone.)
Third,
do not try to move apps to the card. Aside from not actually freeing up much storage (you don't actually "move the app", you move each class in the app separately, and there's a link left in internal storage for each one - and classes aren't much larger than links), a lot of apps won't run from the card. (As for the 64GB card, the phone can't handle anything larger than 32GB.)