I’m often asked for recommendations for Google Analytics courses. In terms of classroom training days, I don’t have any personal experience recently, but if you want to learn online, there are a lot of resources, many of them free. I’d certainly suggest that you at least try this option before committing to spending hundreds of pounds and taking days out of the office.
There’s an excellent summary of what’s available on the Practical Ecommerce blog in 21 Free Tutorials for Google Analytics. There are beginner guides, a link to Google’s own Analytics Academy, and some more advanced hints and tips articles. More than you’re ever likely to need to know, to be honest. Now all you need is the time.