An editor takes footage that already exists and makes it worth watching. It is the cheapest way to get more out of material you have already paid to shoot, and the most commonly underestimated job on this list.
Editing is priced per finished minute, per deliverable, or by the day. Revisions are the thing to pin down: two rounds included is the normal shape, and an edit with unlimited revisions is either expensive or about to become an argument.
Send the brief and the footage together, and say which platform each cut is for. An editor who knows one version is for a 9:16 feed and another is for a website will frame and pace them differently rather than cropping the same cut twice.
You say what you are trying to achieve rather than what to buy. Lucy shapes it into a brief, prices it against what people here actually charge, and shows you the creators who can do it. You agree a figure before anything starts. The money is held until you approve the work, and Lucy takes 15% of the creator’s fee — never a fee from you, and never anything on approved expenses.