If your new to paintball many never think of this. Invest in some kind of pod carrier. The ones that attach to your belt are ok but will be in the way if you crawl a lot and offer no protection if your hit. A more advanced carry system is the vest. If you get a vest make sure you can relocate the pod carriers to adapt to your needs. A vest will offer some protection when you walk in to a ambush or kill zone. A vest can hold much more equipment and if you play long enough you'll know what you've needed in a pinch. some items that are nice to have are in no order
1 water
2 squeegee
3 towel or rag
4 a battery that operates your whatever
I can go in more detail on nice to have items for the newer person in time