What does it mean if it looks like my newborn has acne?

It is Normal! Newborn acne is a common occurrence in babies starting around two to three weeks of age and usually easing up around six weeks of age. Babies develop a pustular acne over their head and face which can even extend down to their shoulders and upper back. It is really a normal variant caused by shifting hormones after delivery. It is not associated with teenage acne, and needs no treatment!
Likely not worrisome. Infant acne, cradle cap, milia, and miliaria - all common in newborns and can look similar. In general, they need only minor care, if any. Even the benign but scary-sounding "erythema toxicum" can sometimes look like acne though the lesions fade readily. Yet, it may be something more important and, as with most any rash, the only way to know for sure is to get it evaluated by baby's doc.
It's Normal. Many babies get an "acne like" rash in the first month of life. We don't really know why, but we do know that it goes away, does not scar, does not hurt and does not mean that they will have acne later in life. There is no treatment. Just clean the skin with a gentle cleanser and use a sensitive skin moisturizer.