In PCBWay you only can buy the raw PCB, the board with no componentes soldered. You have to buy the components in other site and solder them. You can check the Bill of Materials section and the Electronics page for more info!
The SMD-Stencil helps you to apply the solder paste (if you are using it to solder), but it is not neccessary (I didn’t used it).
Hope it helps 😉