I have like lilttle balls behind my neck inside it feels weird what are those am worried?

Lipoma vs. Cyst. The most common cause of ball-like masses under the skin are lipomas and sebaceous cysts, both of which are benign (not dangerous). They could also be the curvature of your cervical vertebrae, i.e., your spine.
Lymphadenopathy. These "balls" are probably swollen lymph nodes. If they are mobile and recently developed they are probably due to a recent respiratory infection. If they fail to improve( get smaller) or grow or become painful please see your doctor or an ent!