social security tax on 1099-NEC income

I have entered my 1099-NEC income in Turbo Tax. What is making me not comfortable is that there was a refund. I don't understand. My gross income is $7500, and turbo tax calculated a $1239 refund. It is making me feel that I made a mistake.

 

In addition, I want to know how do I pay social security tax on this income? please explain.

 

Best...

 

Tarek