Just to add to Watermom's advice:
You CAN add "Liquid Shock" but ONLY if it is Sodium Hypochlorite. Anything else labeled "Liquid Shock" will make your problems worse.
But you can also just add regular bleach (unscented, non-sudsing, and NOT "non-splash") because that is Sodium Hypochlorite as well until we know more.
But how much? We don't know until we know how big your pool is (how many gallons). So fill out the forms.