Not specific to any one spellcaster class but cover all of them here...
How do Staves Work? https://2e.aonprd.com/Rules.aspx?ID=748
Creating a Personal Staff https://2e.aonprd.com/Rules.aspx?ID=1500
Spell Level Access By Level
| Spell Level | Class | Dedication |
|---|---|---|
| 1 | 1 | 4 |
| 2 | 3 | 6 |
| 3 | 5 | 8 |
| 4 | 7 | 12 |
| 5 | 9 | 14 |
| 6 | 11 | 16 |
| 7 | 13 | 18 |
| 8 | 15 | 20 |
| 9 | 17 | - |
| 10 | 19 | - |