Connect the ISP box at the correct socket and complete its activation. Orange Livebox, Free Freebox, SFR and Bouygues equipment comes with provider-specific cabling, labels and setup steps. Support lines often operate only in French, so I can handle the technical conversation and explain the result in English.
Navigate the router controls without guessing. Some box administration panels are French-language only and offer no English toggle. I can identify the Wi-Fi, security and device settings, change only what is needed, and leave the network name and access details documented in a form you can understand later.
Test coverage where you need to connect, not beside the router. Thick walls, long corridors and several rooms make older Paris apartments difficult for a single box. After checking the signal around the flat, the practical answer may be a better box location, a suitable access point, a repeater or a mesh system.