You can easily generate Google Sheets PDF links via Google Drive to share them as PDF files. There's no need to convert them manually. See the instructions here.

Figure D From the Files app on a Chromebook, select a PDF, then choose View. This opens the PDF in a new browser tab that includes annotation options. 6.

Open a PDF document using your Mac’s built-in Preview app. (If you don’t have a PDF document handy, you can create one with your favorite word processor and save it as a PDF file.) ...

To properly sign a PDF on your Android phone or tablet, you'll need to download an app from the Google Play Store.