When heading to state pre OCS, is it your responsibility to purchase what's on the packing list or will it be provided?

Some of the items you will want to purchase but most of your gear should be provided by the unit you are completing your Phase 0 with. You will probably go to another state for Phase 1 and they won't have all of the items you need. Good luck!

If I were you, I would purchase it as you'll need it and the RTI may not have the items or not enough of them.
I went through state OCS and bought everything they required that I didn't have issued. Some of its BS stuff but having been a OCS company commander, they have their purposes. The ones who didn't have everything on the packing list, paid...in other ways. LOL

Unless it’s TA-50 it is your responsibility. Unlike the enlisted side of the house, Officer’s don’t get an annual uniform allowance. The only one you get is your initial uniform allowance and that’s to purchase your ASU’s or have them converted from enlisted to Officer. So anything that is not TA-50 is up to you to have with you on Day 0. Now, caveat to this, this applies to Federal OCS, but I would make the assumption on your part that it would also apply to State OCS. Better to be safe than sorry. But if they provide a packing list, it’s so you come with those items in hand.