Celeste in the City (2004)

Small town girl Celeste Blodgett moves from Bangor, Maine to Manhattan when she gets a job with the New York Examiner, but hears there it's only fact checking, with little prospects for real journalism. Her welcoming young flat neighbor Kyle Halley in an interior designer, who helps her to give her apartment a make-over. At a party she learns her cousin is gay and goes by the new name Dana Harrison; he promises to teach her the city way with a fashionable image transformation, which succeeds with the help of various gay friends. Now she's ready for social life, hoping to impress her boss, reputedly womanizing magazine section editor Mitch Tanzer. He accepts to read her work, but says he can't use it because it's unethical given their personal relationship- then she finds reality is different.

Unfortunately the movie Celeste in the City is not yet available on HBO Max.