Self employed

My Gross Income is $65,462. Net Income is 13,728. 

I try to understand it is because I paid $41,692 to purchase a Tesla, but I use my Tesla Uber only earned 31,838, which is a loss of $9854 on Uber. Is the reason my Income Tax is 0? How much it will be if the Net Income is positive? How to calculate the percentage of the rate?

My Self-Employement is $1940. So, the percentage rate is 1940 ÷ 65,462 = 0.029 ≈ 0.03. My self-employment Tax rate is 3%. Or, 1940 ÷ 13728 = 0.141≈0.14 it is 14%?