You’re thinking of misandrists. Feminism is about equality of the sexes. Other groups (eg misandrists and terfs) sometimes claim to be feminist as a cover. A feminist believes men and woman are equals, a misogynist believes women are inferior, and a misandrist believes men are inferior.
Seems reasonable enough to me if you bought a ticket for a train which doesn’t have assigned seating, which is pretty common. Just choose your seat as you board the same way you would with a bus.