Every file you upload to your website – whether in the files tab, or directly into your page content – will appear in the asset library on the files tab. To get there, make sure you're logged in and then go to the red admin bar on the left > Assets then choose the Files tab:
Display and filtering options appear at the top of the list of all your files. The fist two icons let you choose to display as a list, or as thumbnails:
The other options allow you to sort (by most recently uploaded, or by name), search for any keyword within your files*, filter by type (PDF, JPG, etc), and even filter for all files used in a certain way:
*Note that your PDFs must be text-based to be searchable. To create a text-based PDF from Word, for example, either export as a PDF or print to PDF directly from Word, don't print it on paper then scan back to PDF form.
The filters are additive - for example, you can filter for all PDFs used as Agendas, then change the display back to a list:
When you're done, use the Reset button to clear all the filters!