Yes, you have to file since you had self employment income. Complete Sch C.
I'm an employee for a company though they just pay me off the books, in cash. They didn't give me a 1099, so I just want to know if it's even worth it to file taxes or if I even can file.
The IRS requires that all income you receive has to be reported. You will have to report your income on Schedule C Profit or Loss from Business. Because your employer did not give you a W-2 or 1099-MISC you will have to report your income as self-employed income.
If you had a W-2 for $2739, you would not have to file because that is less than the $12,200 filing threshold.
But, income, other than W-2 wages is treated differently.
If you are paid off the books, in cash, you are not an "employee". You are a "contract employee" or independent contractor. The IRS considers undocumented cash income (no W-2 or 1099-MISC), for work performed, to be self employment income. Enter at "Business Income & Expenses" and TurboTax (TT) will complete Schedule C or C-EZ for you and allow you to deduct any expenses associated with this income. You'll also have to pay self employment tax (social security & medicare tax) on any "profits"greater than $400.