Need help with AE and changing template features

Hi, I’m working on a short 1 min piece with a template from videohive. It seems pretty straight forward but things are going sideways and I don’t know AE much past beginner.
All I wanted to do is replace images and video into the holders but I am no where with resizing of both video and pics.
My template is 1920, the video is 1280… I want to downsize the template to fir the video and I want to scale down the images and move them around for placement.

I would love some knowledgeable help. It seems straight forward…lol