Some laptops have a system where, when the laptop isn’t using much power, there is no reason to have the fans on. Because having the fans on also use power. But when you start to do some heavy stuff, like watch movies or play games, the fans kick on to prevent overheating. So don’t worry if the fans kick on & off every now & then, it’s very normal. To check for overheating, just feel across the top & bottom to see if there is some unusual high heat emitting from it. A high heat would be a temperature at which you can’t keep your hand on the surface for too long before feeling like it is going to burn you. There are some programs out there that will let you manually control the fan speed, but use those at your own risk.