If you have a Sky Broadband router hub, wait for it to be sent out to you and for your activation date.
When your activation date comes around, find a good spot for the router. This is usually without any interference from other devices like mobile phones, and out of the way of any furniture. Ideally, near a computer if you have one, so you know it’ll get the best signal.
Follow the instructions in the manual you’ll have received so you plug all the right cables into the right ports, then turn on the power cable to power on. When all the lights turn green, you should be good to go.