How do I adjust the starting view for a 360?
For share links/embeds, the starting viewpoint (direction and zoom level) the window is set by what you're looking at when you generate the share link. When you click the “Create Link” button the camera parameters are recorded into the link (this is also what’s used to generate the preview/thumbnail image.)
If you don't like the orientation of a link you can re-set it by disabling the link, then setting the camera where you want, then clicking the "Create Link" button again.
If you're comfortable with adjusting URL parameters you can take a look at the full list of available parameters (see related article)