Your guests will need to download and be able to operate the latest free version of Zoom (download here). They will need either a laptop or desktop computer with a microphone and camera. Most laptops come with a microphone and camera pre-installed. Encourage your guests to use computers, NOT phones or tablets. Using these other devices will result in a less fun, limited experience. They will also need a good internet connection and will need to turn off any interfering devices that might make their signal weak (like that gamer in the other room, their smart tv, etc).