If your PDF documents are opening in a program that's not Adobe Acrobat/Reader, you may just need to change the default app for PDFs.
NOTE: It would be worth clicking on the Windows symbol in the bottom left of your screen and searching for an Adobe product first
- Open Default Apps
- Scroll down to 'Set default apps'
- Find the Adobe Acrobat DC and click Manage
- Click on .pdf and select your application
- Your PDF document should now open in your elected Adobe product.