A couple cannot, ipso facto, be Autoentrepreneurs - the very fact that there are two of you, precludes you, ifaik, as the scheme is for individuals. Thus, you 'd have to just register one or the other and then if you ran into problems I'm not sure where that might leave the second person in insurance terms!
I was looking at this for somebody else a while ago and what I did find were several French compaines who do this who were looking for employees. That might be a route in - ie working for somebody else with an already-established business. Yes, you'd earn less I guess, but you'd avoid some of the horribly complicated tax and insurance issues involved in setting up businesses here. Just a thought.
"I couldn't sleep very well last night. Some noisy b*ggers going around in automobiles kept me awake." Ken Miles