So cool that you've gotten far enough in the game to start making some products! We can definitely help you out here and walk you through the steps.
First, we need to make sure the Mill and Pot Flour are both unlocked! You can access Flour at level 10, which is when you first unlock access to the Mill.
The Mill produces the following:
- Pot Flour x6 (1 worker)
- Pot Flour x12 (2 workers) *unlocked at level 19
- Pot Flour x20 (3 workers) *level 26
- Blonde Hash x1 (4 workers) *level 28
- Red Hash x1 (5 workers) *level 56
- Widow Hash x1 (6 workers) *level 76
The first product you'll be able to make is 6 Pot Flour! You'll just need to provide enough Homegrown buds to fulfill the ingredient requirements. All in all, the whole process takes 12 minutes, but you can always speed it up with Potbucks if you want.
Remember that you will need to perform maintenance on these contraptions with Materials after you run them several times, so be prepared for that!
You can also make Pot Flour using various Gizmos! For more about Gizmos, check out this article: What are Gizmos?