You don't need to do anything with audiencing for SLK to work.
The 2 main causes of not seeing your assignments are:
1. The web part has a property controlling whether to show only assignments for the current site, or all assignments. By default it is just for the current site.
2. The web part will function in learner mode unless you have the SLK Instructor permission on the site that the web part is present on. To view your learner assignments if you are an instructor, you will need to place it on a different
site where you are not an instructor, and edit the properties to show from all assignments.
There are also options in the web part to force a particular view to show.