
Dry needling is small part of acupuncture, more focused on muscles. It focuses of trigger points. Trigger points can be a painful point, which has been researched modern era. Dry needling has been adapted in the western world. So everybody does dry needling with short education.
However, Acupuncture is all about using needles. They treat all kind of disease with needles. Acupuncture include dry needling when it treat muscle pains. To understand acupuncture, you have to learn energy flow and philosopy of Eastern Medicine.
I, personally, recommend that you should get acupuncture or dry needling from acupuncturists, because thier main tool is needle.