Question How do i wipe an old hard drive?

Yes.

If you have an available bay in your new pc then the drive could be installed there and wiped.

However, I would use an external enclosure or adapter with its' own power source to connect the old hard drive.

Then wipe.

What you must be very careful about is to pay careful attention to the drive letters. You do not want to inadvertently wipe C:, D:, or some other important drive.

Which should all be backed up as a matter of routine.

Another option is to take the old hard drive apart. They have a powerful magnet inside which can be quite useful so save that.

Remove the platters and scratch the platters up. Then recycle all into the electronics bin somewhere.

Taking the drive apart does not require you to buy or borrow any enclosures. You may need the necessary small screwdrivers.

FYI:

https://www.makeuseof.com/tag/take-apart-hard-drive-magnets/

If there are younger family members about they may enjoy helping....