Social Interactions are guided by ability checks, player ingenuity, GM control, or a combination of these. See PHB p. 186 and DMG p. 244. Try roleplaying when interacting. 

Given the situation, the GM could call for a Charisma check involving Deception, Intimidation, Performance, or Persuasion, or a Wisdom (Insight) check if you try to determine a creature's true intentions.

The GM decides if advantage or disadvantage is warranted. See also Aiding the Check (DMG p. 245), Parleying with Monsters (TCoE p. 148), and the charmed condition.

If an ability check is required, the GM determines the Difficulty Class (DC). See PHB p. 186 and DMG p. 244 for guidance. House Rule - the GM considers: 

  • How ambitious your objective is;

  • The creature's challenge rating;

  • The creature's Charisma or Wisdom score;

  • The creature's attitude.

An encountered creature's attitude can reflect many things, including its alignment, its circumstance, the opposing character's behavior, and the creature's sympathy or hostility toward one or more of the elements of the opposing character's identity