Chris, I fear you are getting just an 'initiator' into setting up any sort of business here, and why I diligently advise any and all NOT to do it. Others will advise you differently I am sure, but the problem is quite simply 'red tape' and bureaucracy which applies now just about as equally as if you are a major company or an individual.
Not only is this a nightmare to contain, let alone handle there is also something that is not that well-known, and that is, it is almost impossible to 'cease trading' to stop the flow of paperwork.
A friend of mine opened a restaurant on his property, and ceased actual trading some six years later following a divorce. This was almost twenty years ago, and when we last talked about this he was still having to provide zero TVA returns and other paperwork on his ill-fated project!
As others have mentioned the AE system is all very well, but they keep moving the goalposts eg the Social Charges being applied - yet another piece of paperwork. It can become a nightmare, so take the best advice you can find, but tread very warily. What is fine today, can easily change tomorrow.
When I considered the AE route for a book production facility here some years back, I too was required to 'take a Marketing Course'. At the time I was Professor of Marketing at European Business Schools, and United Business Institutes based in Brussels, teaching both BBA and MBA levels, with published books to my name internationally. All of which was duly dismissed as not valid by the local (Cahors) Chamber of Commerce - who of course would know better and more about Marketing than me wouldn't they?
That was warning enough for me, and the business remained in Australia. I am sure similar stories abound.
Last thing I read a few months back was that only Luxembourg has higher charges than France in the EU - which, if true, probably makes it pretty high on the list worldwide.
Sorry to be so negative, but I spent a lifetime (55 years) in Marketing internationally, and had businesses registered and running in 8 different countries at various times - from Asia to Eastern Europe, but could never fathom out a way of working sensibly - let alone profitably, in France. I love this country, but it is not business-friendly.