There could be a lot going on here.
First, if you are in the US more than half the year, you will be a resident alien and you will file a regular form 1040 tax return. If you are here less than half the year and are a non-resident, you would file a 1040-NR as mentioned. (Use the substantial presence test https://www.irs.gov/individuals/international-taxpayers/substantial-presence-test)
Even if you are not legal to work, the IRS wants your tax return, and they won't refer you to Immigration. But if you don't have a social security number valid for work, you will need an ITIN, international tax ID number. You will apply for the ITIN when you file your first tax return, we can advise you at that time if needed.
You say you are paid in tips? That is probably not legal. You are probably required to be paid at a least a minimum wage, plus tips. The minimum wage for servers may be lower than for non-tipped jobs, but it is still required.
As a tipped employee, you are required to report your tips to your employer daily. Your employer will take taxes out of your paycheck based on your wages plus your tips, and send that to the IRS. You should be getting a detailed pay stub each week showing your wages, your tips and your taxes. You should get a W-2 at the end of the year. Here is more information about the responsibilities of tipped employees.
https://www.irs.gov/businesses/small-businesses-self-employed/tip-recordkeeping-and-reporting
If you participate in tip sharing, don't report your total tips, only report the amount you kept.
If you are not getting a regular paycheck and pay stub and minimum wage, your employer is breaking the law. I would find another place to work. You may also want to file a complaint with your state labor relations board (check your state government web site.). There is a way to file a tax return and pay your taxes without a W-2, but I would rather not discuss it now, unless you really are working under the table and plan to keep it that way.
