What should I fix first?
Script notes arrive as a flat list, which quietly suggests every problem is equal and independent. Neither is true. Tick what you were told and get it back in the order that stops you doing the same work twice.
Free tool
What should I fix first?
Tick every note you were given, in any order. You will get them back as a sequence of passes, with the ones that would waste your time held until last.
The ordering rule is that notes have dependencies: anything you fix near the foundation changes what is built on top of it, so line work done early gets deleted by the structural pass that follows. The full framework is explained here, including what each pass actually involves and how long to expect it to take.
Do you have the notes yet?
This tool sorts feedback you already have. The PreList produces it: upload your screenplay and it reads your actual pages against 11 core metrics and 51 subcriteria, then builds the ordered plan for you and gives you somewhere to do the rewrite with the notes beside the page.