FIrst problem-Particular layer should be 2D. Second problem-Particular camera has not been set to comp camera. See if that fixes things. If not then make sure AE and Particular are up to date.
Hmm how do I set the particular camera to the comp camera? thank you by the way- I'm very new to this
Just twirl down the camera options in the effects control panel. It is near the bottom. I'm no where near a computer so I can not put up a screenshot.
You should go to Red Giant Software and go through some of their training on Particular. It's better than 99% of the others you will find using Google.
One more hint. Try typing a keyword like particular in the Search Help field at the top right corner of AE. I've been using AE for 20 years and I use that feature about once a week to look fit better ways to do things, learn new features or check on things I have not tried or used in a while.
thank you! those videos are already answering my questions