If your manuscript is complete, I can conduct a final edit and write a proposal/synopsis for an agent or traditional publishing house, should you choose to take that route. This is the final stage in preparing your work for submission and will give it the best chance of publication.
One thing is certain: you cannot edit your own book.
Depending on the condition of your manuscript, there are (at least) three stages of editing: structural edit (manuscript assessment), line edit (copy edit), proofreading.
A structural edit takes a wide angle view of the manuscript and considers such concerns as plot, characterisation, language, point of view, setting, dialogue, pace, tense, cliche, symbolism, exposition and release of information. This sounds complex written down, but it is merely a review of whether the manuscript ‘works’ according to the standard it sets for itself. No amount of copy editing can correct an implausible plot.
A line edit will make sure the sentences make sense and will look closely at repetition, continuity, language, unnecessary padding and word choice.
Finally, proofreading will ensure the conventions of publishing are adhered to, such as spelling, punctuation, grammar, use of italics and capitalisation, etc.