As has been suggested already, you need to know the starting wattage of the appliances you want to run and sum them to get a properly sized generator. You also want an inverter generator, which produces clean power that will not destroy sensitive electronics.
I bought the Honda EU2000i four years ago. It's a great machine and very quiet. I've never lost power for even a minute, so it's never been used for emergencies. But I do have a barn that isn't wired for electricity yet, so I've been using it to power LED lights totaling 40 watts of consumption. When I start a 6 horsepower shop vac, the lights temporarily shut off and the breaker nearly trips as the vac uses a ton of start-up wattage. So this gives you an idea of how little you can do with a smaller generator. It's great to run your tank, but won't do much else.