Hey there!
You can restore files from the "events" tab of your Dropbox.
If you're unable to find a file in your Dropbox account, please refer to the tips here in our Help Center:
https://www.dropbox.com/help/969
This page covers a wide variety of situations and solutions.
If there are too many files for you to restore on your own, please refer to the section titled "Help! There are just too many files to restore".
Please let me know if there's anything else I can do for you.
I hope this helps!