curtir is colloquial and modern, to enjoy something, and also "to like" a post on social media in Brazilian Portuguese; usufruir is formal or legal, to benefit from or enjoy the use of something, a usufruct.
curtir is colloquial, to enjoy something in general; gozar also means "to enjoy," but can carry a sexual connotation, "to climax" — worth knowing to avoid an awkward mistake.