I have never taken a sailing lesson. I grew up sailing a sunfish like boat and my uncle's C&C 24. After several years away from sailing (college until I was 30), my wife and I bought the C&C 24 from my uncle. I remembered most of the basics and read a couple of books.
The one thing I would recommend is a boating safety course. We have the US Power Squadrons and Coast Guard Auxiliary that put them on in the states. I am not sure what you have but something that will cover who has right of way, how to read a chart, how to plot a course, what safety equipment you should have and how to use it. That kind of basic stuff. You could even do them online. The US Power Squadron American Boating Course is available online.
How is the boat shopping going?
“Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover.” -Mark Twain