Hi, welcome to the community.
A ".caproj" file cannot be opened without the project files. You'll need to choose "save as a single file" to save the file as a ".capx" (a compressed file of your entire project), then share that file.
Also, most of us use Dropbox here, it's fast and easy, with no ads or captcha tags etc..
That being said, I'd be happy to have a look at your .capx.