Creating a sheet that pulls columns from other tabs

I have created a Google Sheet with multiple tabs for individual project schedules. The individual schedules have two columns: one with the tasks, a second with the project's name and the due dates. I want to make a top sheet that pulls the date column from each individual project and runs them side-by-side so everything is in one sheet that dynamically updates as the individual schedules change. (An overall view.) I have tried Importrange but it doesn't seem to work and says it cannot find the sheet or the range. Not sure if it is glitching because I'm trying to pull from the same worksheet into itself.