Stroke Illustrator HELP

[Hwhiskey]

I'm currently losing my mind in regards to adding strokes in Illustrator. I am in no way a wizz at this program, so i may have missed something basic. I saved my work as a PNG, and placed it. If i add a stroke via appearance or any other way, it simply does not work. I am currently in 'image trace'. If i rasterize, it still doens't work. I want a stroke to go around the outline of the whole image. I have had it working, which is confusing me and infuriating me even more. Most suggestions such as 'Object Outline' etc are greyed out. 

[Doug A Roberts]

After using Image Trace, click on the 'Expand' button in the Properties panel. Then you'll have paths to work with.

Initially, the image trace is 'live' rather than 'expanded' in case you need to adjust the trace settings.

[Danny Whitehead.]

How was it created before you saved it as PNG?

[tonyharmer]

Once you've expanded your trace, group it all together and follow the directions in this video: https://youtu.be/jAhWaR3n1Zo