Saving PDF on iPad for future uploading use

I'd like to be able to apply online for jobs using my iPad. I have a PDF version of my resume sitting in my gmail but am unable to find a way to save it on my iPad so that I may select it for uploading to job sites. I've downloaded Google Drive but still can't fnd the resources to explain how to store the file for future uploading use not just for viewing. Any suggestions?? Thank you!