What can I do about itching on the top my feet?

See a doctor. You can see a doctor to evaluate you for the possible causes of itching on the top of your feet. While you are waiting for the appointment with your doctor, you can try over-the-counter Hydrocortisone cream. It may well be something like irritant contact dermatitis.
Need to know more... Is there a rash or other problem there? If there isn't, sometimes dry skin is the problem, and you can use a non-allergenic moisturizing lotion on your feet. Sometimes a foot powder will help too. If there is a rash, or there is pain, discharge, or a lot of swelling, you should see a doctor. Also, if you are a diabetic, you should see a doctor about problems with your feet, no matter how small.