Scrivener for my second laptop

I’ve couple of questions for you. Right now I am working on a screenplay. I tried emailing part of my work as an attachment to my director, who’s using my other MacBook Pro, so that we can have a discussion about the project. Not only can I not attached the documents, I ended up losing all my work!
May I know what happened?
I tried downloading the “work” onto my thumb-drive and that didn’t work either. How do I then also load Scrivener onto my MacBook Pro? Please help. tks.

It’s best to export or copy-paste a chunk of text to a word-processor, and then share it with others. Trying to share Scrivener projects can run into complications. Think of Scriv as a place where you outline and draft, but the word processor is for finishing work and sending it around. The tutorials and FAQ will offer more help on these concepts and procedures.

This is from the FAQ Not Yet Published; excuse the wiki syntax please:

What druid said is good advice though, especially for a new user. Once you are more familiar with the Scrivener project file you could probably devise a safe method for sharing it with others. It would require one person to not edit or write anything while the other has it, though, since there is no way to “merge” two different copies together simply. And the whole project would be transferred using the backup to with zip archival feature, most likely.

Thanks for the advice.