Hi Jose,
For your First question we need to know these details.
What is the Transaction you want to call? What is the Program name?
For your second question,
There are several methods to debug a Background Job. One Example is as follows (More Technical)
1. Put a WAIT UP TO 30 Seconds in the Program after JOB_OPEN.
2. Execute the Program and Goto SM37.
3. Select your job and Click on the Application Servers in SM37
4. It will show list of Servers, Now Select the Server and Click on Processes (Black Screw Symbol)
5. Now Select your Program process and fromt he Menu you will find option Debug.
Hope this helps..