Oh I see, so you were looking for information on item storage. Yeah once you are familiar with the names this game uses for things then you know what search terms to use for information.

We have the dresser (inn rooms) which stores equipment only. Also the armoire (inn and player housing) stores certain specialty equipment. Icons along the top edge of equipment tooltip window let you know if the item can be stored in those chests or customised with your fc crest (guild emblem).

For general item storage, yes hiring retainers is the answer. If you join an fc (guild) you also have access to the fc chest (in most cities and player housing) which is shared storage between the fc member with up to 5 pages to unlock based on fc rank.