In order to ensure that things work as smoothly as possible, make sure that your AppleTV is turned on and facing forward. You should see a small white light indicating that it is indeed on. If the unit is facing in another direction, the signal will likely cut out, so the positioning is important. Then, make sure that your television is on. It happens to all of us, so just make sure.
Each television has been set up to work with a specific wifi network. This should be visible when the AppleTV is on and the pictures are scrolling. The reason for this is to avoid overloading any one specific network. Make sure to choose the network that matches your specific television set up. If your iPad is on a different network, the connection just won't work.
At times, our routers need to be reset. If your television says to connect to "Upstairs 1" for example, but you can't see this choice on your iPad, tell someone in the office and it will be reset. It takes mere minutes.
If you feel the need to explore the AppleTV and use some of the other functions, please make sure to return it to its original state. Just like a whiteboard, leave the room as you found it. Respect your colleagues.