The simple, common (growing less common)
usage is “Is there something I can help with?” Not
ending with a preposition, with the approval of a
high school sophomore English teacher, and more
often written than spoken, “Is there something with
which I can help?” Either way, spoken genuinely,
gently, caringly, compassionately, the world melts
with “Sure. That would be nice,” or “No. That’s okay;
I’m okay, but thanks,” or a shake of the head, yes
or no and a smile or tear or both — of gratitude.

*Once when I was having a frustrating time with
our new rescue Lab, a person, passing by, stopped
the car and, and with an air of superiority and
a tone of moral judgment, feigned an offer to
help but really wanted to put me down with an
accusation after a gross assumption of what was
transpiring. If that person simply had asked if
I needed help in a voice that confirmed the offer,
I believe everything would have been different;
I believe everything could be different, if….