First, did they ever work, or is this a new problem?
I would physically reset all GFCI outlets and all breakers in the panel to confirm that they are indeed ON.
Next, what does work? There should be multiple circuits. How many? What do they go to? If there is 120v AC power to one or more other circuits, then incoming power is not the issue. The outlets that do not work, do you think they are connected to a GFCI outlet? Do you think they are all on one circuit? If the former is true, then a GFCI outlet needs to be reset, or it could be faulty, or wiring could be wrong or disconnected on the load side down the line. If the latter is true, then the breaker needs to be reset, or it could be faulty, or wiring could be wrong or disconnected on the load side down the line.
Are there any inverters that could power that one circuit instead of the regular method? Anything else out of the ordinary that a previous owner may have done?
Beyond these basics, testing, diagnostics and repair need to be done, and you should hire an electrician.
Best-