If you want to have the same info screen project from a single PC show up on multiple screens at the same time then you need a magic hardware ingredient called a video splitter. That is a device that allows you to distribute video signal coming from a single source (a PC running your info screen project) to multiple screens simultaneously.
A video splitter is sometimes also referred to as a video distributor or a distribution amplifier with basically the same meaning. Anyway, here is a conceptual diagram of this type of solution so you get a better picture of its role in an info screen system.
If you want to use a video splitter in your info screen solution then look for one at your local computer hardware supplier. Unfortunately we can not recommend any specific model nor manufacturer, but we can give you some general tips that will help you ask for the right thing. Obviously you should know how many screens you want to have in the system and then also the screen resolution, type of video connection (HDMI, DVI, VGA) and cabling distance from the signal source. Knowing these parameters will help a professional recommend you the right equipment or ask further questions.