I'm happy to see your progress! Rolling is done on the Items or Gear table, depending on what you feel or want to find. Alternatively, as you mentioned, you can roll 1d12 and use the result across the 12 possible Items or Gear.
The d12 was a popular piece of feedback I received during testing, but I stayed with 2 1d6 tables to allow players to pick what they find based on how they are currently feeling about the delve. I really wanted to provide ways to "un-stuck" the story, which an opportune Item or Gear can provide.