Potions may be consumed as Actions or Bonus Actions.
As an Action, character gets the maximum possible benefit of the potion. No rolls are required.
As a Bonus Action, character rolls for benefits.
As an Action, a character can "feed" another character a potion. That potion can exist in either party member's inventory.
A potion can be thrown up to 30 ft with a successful DEX check (usually DC 10)