Zero Experience - Where do I start?

I would phone a few of the hundreds of sailing schools with yachts, see what they can offer in terms of introductory courses.
Personally I would advocate doing a short course first, without your family, as it might be less pressure. Equally when I have sailed cruisers, knowing that my wife was competent to steer the thing, understand the sails and sort out rudimentary navigation was very important.
You may find the reality is not what you thought. You may love it. Best to make sure before spending lots of money or time. Some people only find out its not for them after they've downsized the house to buy the boat.
Ask lots of questions, read lots of books.
Talk to people. I did Yachtmaster theory at evening class as a starting point, having sailed dinghies as a child. Good way to meet people with similar ideas.
There are many facets to sailing, you may find your interests better served on the ybw.com forums.
Lots of people do buy largish boats without a dinghy sailing background and get on fine.
You don't need to be a competent dinghy racer to be competent at getting a yacht from port to port across oceans, there are whole different, but complementary, sets of skills.
The whole big-boat thing is expensive, money spent on learning is usually good value in the end.

Or you could move to the south coast, join a club, buy drinks for yacht owners and hope they invite you to the next foray to France in return for a bit of help with maintenance. That can work too!