To setup  HP Envy Pro 6420 All-in-One Printer, start by unboxing the printer and removing all packaging materials. Plug it into a power source and power it on. Install HP Smart app on your smartphone or computer, as it will guide you through the setup process. Load paper into the input tray and insert the provided ink cartridges. Use the app to connect the printer to your Wi-Fi network, complete alignment, and start printing or scanning effortlessly.