When you upload a file to DocHub, you have the choice between creating a single use document or a template (master copy). If you would like to keep reusing the same PDF document and create a new copy for each signer to fill out, you'll want to upload it as a template on the New Template page. If you only need one version of your document (i.e. for single use), you can just upload it as a regular document on the New Document page.
All files opened from Google Drive or Gmail will begin as a regular document, but you can convert it to a template by clicking on File menu > Actions > Convert to Template. For more information, see the bottom section below or see: Creating and sending a reusable template.
Working with Templates
You can also view copies of a template with it open by clicking the View button in the upper left:
If you'd like to share a template for someone to sign or fill out, see these articles:
Sign Requests: Getting Started
Converting a regular document to a template
Open the document and click on File menu > Actions > Convert to Template.