Can I have a cover photo or location set in a template

I would like to have a Template that already has a Cover photo added or a location added is this possible? Follow up to that can I change the default Cover photo when no cover is selected. My concern is if a post is added without a cover a "nice image" can be used by default. This also helps when a post is shared on socail media it will use this nice image instead of the default blank image See site details for more info.