Simple Questions

I've been editing on this for a few weeks now. It seems like it can't hold much data! I've tried clearing files and deleting old ones, and still when I transcode proxy media, it says "Not enough disk space, clear some space and try again" So I do what it says and it still doesn't let me.

Is there a way to avoid uploading massive amounts of data? Honestly, I feel like I don't have an overwhelming amount of footage on there.

I just need basic tips on managing my footage, and how to avoid this.

Thanks