Jose,
Presuming you really have no background/transparent background as in a PNG with trasparency (otherwise switch to that), you can:
0) Preferably, first remove the little dark leftover spot above the shoulder in Photoshop;
1) Use Object>Image Trace, setting the Options to Black and White and a Threshold of 255 to get a filled fully black obejct;
2) Expand the Trace and switch from Fill to Stroke with the required colour and Stroke Weight;
3) If the cut contour is to follow the outer boundary of the image at a distance outside it, use Object>Path>Offset Path with that distance as the Offset, and hide the original path from 2) so you only have one cut contour (you can go back and make a different offset/distance if desired).