English literature is writing in the English language that somebody thought worth keeping — a poem copied into a manuscript by monks, a play printed after its author died, a novel serialised in a magazine and read aloud in a kitchen.
It starts somewhere around the year 700, in a language you would not recognise as English, and it has never stopped borrowing: French after 1066, Latin from the church, and in the last century Hindi, Arabic, Yiddish and Jamaican patois. Every word you are reading arrived from somewhere else.
Which means there is no correct place to begin. Begin with something short and loud — a sonnet, a soliloquy, a speech — and then follow the argument backwards into the century that made it.