Kevin, the warning you see is a compiler warning, nothing to do with debugging.
I think from your image, the green, 'run' button is not lite ? That means you app is running and has not hit any break point you may have set. Yet.
The normal model is to set such a breakpoint in the area you are debugging and then launch and interact with you programme if necessary to ensure that breakpoint is encountered. When that happens, the source window is brought to front and the line you set is highlighted. You can then step through as required.
If you are not encountering the breakpoint you set and expect to get to, maybe thats the bug you are chasing ?
And don't forget you must be in debug mode to use the debugger ....
Davo