Using Flexiforce Pressure Sensor with arduino to trigger projection

I have very little experience with coding and absolutely no experience with Arduino. I am putting together the last details for an interactive art installation that goes as follows: I'm positioning a chair with a Forceflex pressure sensor in front of a wall. When the viewer sits in the chair, the projector switches the feed from a black screen to the webcam feed which will be hosted on a website. I have an Arduino and a pressure sensor but I'm not sure exactly how to go about programing it to read weight, and switch projection view from black screen to the live feed. This is also the simplest approach that I can think to use aside from just triggering the projector to turn on, but there is always a boot-up that takes time, so that option is out. I've tried to create a basic on/off code through Processing (as practive for the Arduino environment) but I'm not having much luck overall. I read that I might also need a Breadboard so that is on the way. I would very much appreciate guidance on coding!