Your age doesn't matter.
If you have more than $6,350 of earned income reported to you on a W-2, then you are required to file a return.
If you have more than $400 of self employment income, you are required to file a return.
Your age does not matter. But if you can be claimed as a dependent on someone else's return, then you must select the option for "I can be claimed on someone else's return" when using the TurboTax program.
Note also that even if you earned less than the above amounts, if any taxes were withheld on your earnings, then you *should* file a tax return so you can get all those withheld taxes refunded to you.