My picture shows only when I initiate the Zoom call

Hi Lilo, Hime-Tama here. 

I'm sure you're aware of this but there is a "start video" option in the bottom left hand corner of the zoom window when you're in a meeting. You should be able to manually enable video if the host of the zoom meeting has allowed participants such as yourself to do so. However, I believe what you wish to do is to set your Zoom up such that it defaults to starting your video when you join a call, whenever possible. To do this, you need to go into Zoom settings, then click on "video". After that, scroll down in the Video menu on the right and look for the checkbox "turn off my video when joining meeting". Make sure to deselect that checkbox. 

Hope this helps you!