where can i find docs for an inventory for RPG ?

i try for a long time to find docs or info for that inventory to script with xml, database, and i can't see the way.

can you help me to find the process to make this with save and load for item and character infos ?

Thanks

There is no official documentation specifically for doing this, but there is a lot of information out there. See this answer which gives some places to find out more.

There is no difference between saving your "RPG inventory" and any other data, so you may want to start looking into object serialization and/or saving data to things like SQLite. These are basic concepts. You should acquire them before moving on to more complex tasks.