At your level? It depends what you want to do.
-You can toss any drop from a monster, those are only really useful if you're getting into crafting (most people wait until they hit a high combat level before doing that so they can one-shot any monster they need to farm). Unless you've scored any drop from a primal, those are a bit harder to come by.
-There's no real point in keeping any gear you've leveled out of, unless you're keeping it for a glamour or saving it for when you're leveling another job in the same roll (like keeping an ironworks set of magic you used for BLM so you don't have to re-buy it when you level SMN).
-Any potion outside of the free Fantsia you get for beating ARR is useless until you hit endgame.
-If you have any food, you should be eating it before any dungeon you run, since it will give you an EXP boost for 30 min.
-Faded Orchestion Rolls are a part of the Alchemist crafting lists, so you probably won't need them for a long while. But they're also random drops for raids/dungeons, so if you do toss them you might have to do some overleveled runs for it later on to get it again, so I'd say keep them in some dark corner until you start leveling ALC.
-Materia is also an endgame thing so anything below IX or X is made redundant just by grabbing the level appropriate Rowena Gear.
tl;dr at your level most stuff is easy to get again, if a little tedious, when you get to higher level and want to re-acquire it for other job uses. EXCEPT THE FANTASIA, THAT COSTS ACTUAL MONEY TO RE-BUY FROM SQUENIX.