First start of the day the truck idles rough and makes knocking sounds

Hello, I'm Danny.

The first thing that needs to be done is to perform a code check to determine the check engine light codes that are stored in your vehicles computer that is causing this issue. Here is a tutorial showing what is involved to check for these codes:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Places like AutoZone auto parts stores can check codes for free. After doing this test get back to us with the code information and we can then properly diagnose. Hope this helps and thanks for using 2CarPros.