my car overheats without smoking and was leaking antifreeze. on 1999 Buick Century

The leaking has stopped, but the overheating hasn't. I was told it was the water pump then told the water pump won't start leaking then stop. What are possible issues? However, when I look in the container, the antifreeze appears to be low. I am not sure where to look, what to look for.

Asked by for the 1999 Buick Century
water pump can leak and stop at times. have cooling system pressure tested to determine source of leak