How to open an electricity/gas account in France?
The main company that is managing electricity and gas in France is called ENGIE.
Once you are in your apartment you have to contact them in order to open an electricity or gas account otherwise the power will be shut down at your house within a few weeks. The standard lead time for a connection is 5 working days.
The procedure is quite simple, all you have to do is to go to Engie website. On the homepage, you can change the language. You can choose whether French or English. Then, you can decide to send them an email (in English) or to subscribe directly to an energy contract (https://particuliers.engie.fr/en.html)