There are thousands of items in Crimson Desert and you will struggle at first to keep everything you encounter with so many activities available and not-fully-explained details, inventory and storage can be extremely challenging to learn and manage in the early parts of the game. Luckily, you can unlock more inventory slots early on and Pearl Abyss has mentioned a true storage is incoming in a future patch.
To unlock more inventory space early on in the game, follow these easy steps:
The easiest way to increase your inventory size early on is rush to Hernand town (or follow the main quest to the town) and hit each major vendor and buy the bags. This will increase 1-3 slots
Next is doing missions for each vendor you find, found under Hernand Commissions in the quest log, and you will increase inventory slots upon mission completion
In a later patch, a storage option will be unlocked but a temporary but dangerous way to “store” items is sell to one vendor, we prefer Rhett in the center of Hernand town, and then if you need the item again, select the Repurchase item from said vendor. Items do reset after 7 days in game so be warned!