This is a difficult question to answer, and you will see that very few copywriters publish their rates online.
The reason for this is that what clients expect from a copywriter can vary a great deal. They might just want some established content rewritten in a clear and purposeful way, or they might need someone to develop an entire strategy for their copy and create an entire site or brochure from scratch. For this reason, the amount of work a copywriter needs to do on a project can vary a great deal, and it's very hard to put an exact number on this without discussing it with you further.
It's the same with charging for proofreading or editing. Some clients just need someone to go through their copy and correct basic typos, grammar and punctuation, whereas others need some substantial editing to make sure the meaning is properly conveyed.
As a rough guide, copywriters charge between £250 - £400 per day, with rates as high as £800+ for specialist, niche writers. You can see how this compares on the annual survey conducted by Procopywriters.
I work right in the middle of this range at around £300 per day, or £40 per hour. For editing and proofreading services, I charge £185 per day, or £25 per hour, and can also calculate a per word rate for you.
However, what can be achieved in this time, and how much time you will need me for, is very hard to pin down exactly.
That way, we can chat about your project and work out exactly what you need. I will be able to give you a few different options and work out some price ranges for you. As we work out the details, I will be able to give you a solid quote and we can agree on a rate for the work. There's no obligation and I won't be pressuring you or pestering you - we'll just discuss the ways in which I can help.