New Enterprise, Previously semi-retired. What to do re Ameli, Social Security etc.

Hi,
I am a bit of a loss here and could do with some (a lot) of help…

We are 57 (me) and 54 (Jackie), both of us United Kingdom citizens, resident in France,

When we first moved to France in summer 2017 we registered with Ameli.  Our first tax returns in Frace were for the partial tax year 2017.

I have transferred my UK pension funds to an Assurance Vie, the income from that is above the subsistence threshold, so we both have our Cartes Vitales and Cartes de Sejours.

In October 2019 we registered a new enterpise “SAS Grange des Dragons” - Fabrication de Bieres Artisanales, electing for impots sur societe. Jackie is registered as La Presidente, I am Directeur Gerant. We each hold one share each.

What I need help with is what I need to do regarding registering to pay our cotisations. Our mutuelle was recently renewed, but I noted that it was only until 6 June. Ameli have just left a message for me because they have no record of our business.

No doubt I had to register somewhere but I have absolutely no idea with whom. We both completed a Stage Prealable d’Installation at the Chambre de Metiers et Artisanats. I thought they had said that they managed informing all relevant organisations, but I am not so sure. The company registration was managed by a Notaire, we did receive a notification from the CMA and a reminder from GREFFE that our information was incomplete.

My guess is that not everything has been done and I need to finish this off properly. Can you please explain what I need to do, and with whom?