It’s crucial to understand this question before attempting to answer any essay question.
To entertain, of course! But Goldsmith also satirises the “vanity and affectation” of refined 18C society – a society pre-occupied with an idealised view of mankind, attempting to create this through appearance and “fine manners”. The play’s themes are linked to this, to ideas of what is real and what is false or fake. As the dandified character of Marlow says, “I owe too much to the opinion of the world, too much to the authority of a father…”