Registering a retreat centre in France with accommodation, meals and activities

Background:
My husband, then fiancee, bought a property in Orne last December that used to be run as a retreat centre with the aim for us to continue with this activity. The property is connected to spring water and has 11 bedrooms (10 for guests and one for us to live in) and two large course rooms. The idea is to offer accommodation, full board with alcohol licence and the two course rooms for groups, for example a yoga teacher to bring their students over and to do yoga in. There is also the possibility of us organizing the activity for the group.

After discussing with the Tourist Office we have been informed that we are unable to open to the public before we have connected to mains water. We are in the process of getting an estimate from SAUR to connect to mains water and expect the cost to be high and to take 6 months to complete. We are planning to register two gite (one a completely self contained little house and the other in the outbuilding a two connected rooms with ensuite) and 5 bedrooms as chambre d’hôtes (three in the outbuilding and two in the main house).

1) Can we register as gite, chambre d’hôtes avec activite and table d’hôtes as one activity? What is the correct classification for us?
2) I am thinking of starting as a seller on Amazon to tide us over until we can open to the public. Currently we are supported by my husbands business in the UK. Is it worth it to register as an ecommerce seller first or both at the same time?