Self employment tax

Hi, I work currently as a seasonal golf caddy. I was wondering which is the best turbo tax product for that. I create the 1099 myself and am wondering if self employment tax is calculated on gross income or gross income less self employment heath insurance deduction being I pay 100% of my premiums. I ask only bc that line was blank on my return last year. Also as a golf caddy should i be paying self employment tax? Thanks!