The first thing to do (which is a good practice reflex to have) is to hide the worksheets used in dashboards. It makes it clearer for the end user.
You can do that by right clicking on the dashboard tab > "hide all sheet"
(it's greyed out because I already hide the worksheets used).
To save/ print to pdf, click file on the top > print to pdf
If you have several dashboard you chose the "entire workbook" or "active sheet". If you have hidden the worksheets used in the dashboards and select "entire workbook", it will save the dashboards views without the worksheet.
Hope this helps,
and what about tableau server? that's my problem