It kinda depends on How you are going to Use the Generator.
Here's Two Examples...
1) My Aunt and Uncle live in Oregon in an area where the power goes out when it storms. When they loose power, Uncle wheels his Portable Gasoline Generator onto their covered Patio and cranks it up. Then he feeds a 2 Big Fat Extension Cords that are plugged into the generator thu a window and Everything they want to Power (Microwave, Lights, Portable Heater, Computer, Radio, etc) get plugged into One of the Two Extension Cords.
2) Their Neighbor has Generator that is Hard Wired to their Main Electrical Panel via a Sub-Panel. When the Power goes out, they Disconnect the Main Power from the City Service, Turn the Breaker On on the the Sub-Panel, the crank up the Generator. Now their Entire House has power. Although they Can't turn on Everything at the same time or it will Trip the Generator. But there are No Extension cords. And all the Lights and Wall Outlets work.
Then when the Power comes back on, they Turn off the Generator, Switch the Sub-Panel Breaker to Off, the Turn On the Main Panel's Breaker to restore City Service.
For most people, they are going to have a Set-Up like My Aunt and Uncle. A Portable Gas Generator that gives you Power from the Generators Outlets. Or Power from an Extension Cord that is plugged into one of the Generators Outlets. It's a Lot Cheaper. And it's hard to Screw something up.