PDF Subfolder

I want to organize all of my PDF files in a /PDF sublink so that they all load into https://www.mysite.com/PDF/pdffilename.pdf.

I have about 300 PDF files that need to be manages and it would be ideal if i could do this through simple bulk upload; however i also want to ensure good SEO.

I tried uploading all of my PDFs into a folder using FTP into the wp-content/PDF; however any link to these files is broken. can’t seem to link to them. Do i need to set permissions somehow?

I’d appreciate any tips about plugins or approaches to manage these PDFs into a /PDF sublink. Ideally i would not have to manually set all of the permalinks in the media folder.