I've heard that you can make a back up for your mod plug in but I'm not entirely sure how to. I'm making a pretty massive mod and just don't want to take the risk of losing it all. Where would I go/how would I go about making a copy? I've tried, loading up the creation kit like normal, and going to the Data File Menu and tried copying the plug in by right clicking on it, but no normal prompt comes up. The only thing that does happen is if I were to normally double right click on it to make it the active file.

Any help would be awesome, thanks.

The CK does this by default I think.

Check your Skyrim main folder, it should have a folder named 'Backup'.

That contains all the .bak files of your esps. To restore them, just rename the file extension to YourModName.esp.