How to change duration times on multiple photos on photo app

Hi, I have used windows movie maker in the past and I am now trying to learn Windows 10 photo app. The only issue that I have is how to change multiple photos that I have imported from an external hard drive onto the story line and I am wanting to change the duration time from the default of 3 seconds to 7 seconds or 10 seconds and change the zoom in and out on multiple photos. I cant seem to highlight multiple photos at once like I did in Windows Movie Maker. Can anyone help as this is so frustrating and not only time consuming to change the photos one by one. Also I have no idea how to send a feed back to Microsoft about this .
Many thanks in advance.