I'm going to tell a homeless person to fuck off
What did the homeless person ever do to you?
Yes, I'm terribly annoyed by them for telling me to also go fuck off when I've said hello.
While it was very rude for the homeless person to curse at your initially, dont stoop to their level and do it back. If the homeless person treats you like this simply let them be. Any anger you feel is simply making your day worse, so its not worth it for someone your not going to ever seen again.
But I feel like I need some revenge for that fuck you.
If you feel like you need the revenge, don't you think it will cause more trouble if you retaliate with rudeness? How about just moving along with your day, because they are strangers and you deserve to be happier than this.