The typical home will have a router provided by the ISP with its own wireless network. That was fine a few years ago, however, going forward it is unlikely that will suffice for the typical family. Now a family of four could have as many as 20 devices on the network, requiring coverage all over the house. This is why it is important to get a network set up correctly with future growth in mind. Here are the components of an ideal home network:
The first point to upgrade would be the router. Internet connection speeds get faster every year, some exceed 100Mbps, which means you will need a router that is capable of gigabit speeds. Also, new routers provide additional features like segmentation, parental controls, etc.
There is no point in buying range extenders and wireless bridge devices. The best devices to get now are mesh-capable wireless devices like Google Wi-Fi or EERO. These units talk to each other and provide best in class performance for homes.
Network attached storage devices, and streaming players work best when connected to a wired network. The best way to do this is to get a router with multiple ports and connect these devices directly. If it is possible, run a cable from the router to a gigabit network switch and connect all devices with physical network ports directly.
There are affordable home security cameras that connect and use the wireless network. The problem is that several of these cameras can use up most of the available wireless network bandwidth. Get around this by setting up a separate network only for cameras. This will also provide additional security.