I recently signed in and some of my documents and pictures are missing

Hi there, 

Welcome to Box Community and glad to assist!

When looking for missing files, you can go and find it in your trash. Also, Box do not delete user files, unless the latter initiated the deletion. 

Notes:

• When items are deleted from a collaboration folder, both the owner and the person who deleted the item can recover the items from the Trash. 
• If you are removed as a collaborator from a file or folder that you've deleted, you no longer see that item in Trash. To see the item in Trash, you must be again added as a collaborator to that item.

The steps below apply whether you’re selecting from search results or from all Trash items.

1. Hover to highlight the row of the item you want. The More Options ellipsis (…) displays.
2. Click the ellipsis (...).  Then: 

• To return the item to its original location in Box, click Restore.

3. At the prompt, click Okay.

For more details, please see this article. 

Thanks for posting!