The back of my neck hurts when i look up. when i don't move it i have dull pain on the part where my left shoulder meets with the bottom of my neck.?

Neck strain/sprain: Often no specific injury, but many people suffer neck/shoulder pain unknowingly caused by long-term desk work (looking at the computer all day) and poor sleep position at night etc... I would suggest doing some really good range-of-motion/stretching exercises; use of some motrin/aleve, gentle-warm heat massage may help. If not better, consult doc for a more complete evaluation. Good luck.

Neck pain: Neck pain can be caused by various conditions, commonly due to muscle strain/spasm. Pain that is worsened by neck extension "looking up" can also be caused by a pinched nerve due to a disc bulge. Discuss with your md as a start for an evaluation.