Shannon:
As you grow stronger, and travel here and there as a seeker, you'll end up with a bunch of supply items some of which you'll need, and others that you won't.
It's not a good idea to carry around too much luggage though. If you're weighed down, you won't be able to fight at your full potential.
That's why I often leave my heavy baggage with the Warehouse Keeper. I happen to have something to deposit with him. Care to head over instead of me? This'll be a good opportunity to introduce yourself to the Warehouse Keeper, too.
"Who do I need to look for?"