10,803 is Less than the Standard Deduction. So you must have been claimed as a dependent. If you are a dependent your Standard Deduction is only your earned income for the year + $350. So you must have had about 10,453 of wages. Oh you said you have Child investments? Then you were a dependent and took the Standard Deduction. Ask your parents.
You would know if you Itemized. That is things like mortgage interest and property tax, medical, Charity on Schedule A. See Schedule A.
https://www.irs.gov/pub/irs-pdf/f1040sa_18.pdf
