The easiest method of creating new items is by using the Soulslike Item Creator.
When you first start this tool, you will notice a few categories. You can open each category and fill in the data as you desire, according to the type of item you are making:
To use your item in-game, all you need to do is add a B_PickupItem actor to your world and select the new Item Asset that you've created through the Soulslike Item Creator:
