Athlete's foot, as you probably know, is a fungal infection of the skin of the foot. It typically causes itching and flaking of the skin of the foot, especially the sole and between the toes. There is often a strong odor as well. If these are the symptoms you are experiencing, then you could start by trying over the counter anti fungal or athlete's foot treatments. There are many of these, including various sprays and creams. Most pharmacies have an entire over the counter section devoted to athlete's foot. In addition to using the spray or cream, you will need to keep your feet clean and dry and will need to wash and change your socks frequently.
In any case, I would start by going to see your primary care doctor
who will be able to diagnose you and help you decide on the appropriate treatment. This is especially important if the infection has gotten into your toe nails (thickening, yellowing, or distortion of the toe nails). Good luck!