I am using a template that I downloaded, but the duration of the media placeholders is only about 4 seconds long, and I would like to be able to change that but I don't know how. Ideally I would be creating this myself instead of using a template but with my limited knowledge and time crunch I need to use one. I tried just to stretch out the timeline like I normally do with my after effects project but I can only shorten them. Any advice would be much appreciated on what I can try to do!
I'm not sure I understand, could you give a little more info? What are the media placeholders? Video clips? Can you just replace them with longer video clips if that's what you are going to use? You can replace layers by selecting the layer in the timeline and then alt/option + drag and drop from the project panel onto the layer or into the comp viewer.