Hi there, SEO is my main job and I work daily on all aspects of SEO issues. For website analysis (on-page SEO, keywords, etc..) as well as for other SEO related things (backlinks, competitors, technical SEO, robots control protocols, link‐worthiness, and other factors... ) I use a few industry leading SEO tools (WebSite Auditor, IBP, SEO SpyGlass, ScreamingFrog, SEO Profiler, etc ). Beside mentioned tools I have over seven years of experience in SEO industry...
If you need only on-page optimization on your website, that could be finished in a day or two...but that also depends of number of pages that your website have.
Take care,
Milan