If you were paid anything, you should get either a W-2 or a 1099. If the employer does not give you one or the other, contact them and ask them for it. If they refuse or brush you off or just don't do it, then you will have to file your taxes with an IRS form 4852. This is basically a form saying "I didn't get a W-2 but here's what it should have said if I had gotten one."
You should also call the IRS and tell them you didn't get a W-2. They will send a letter to your employer warning them that they are required by law to give all employees a W-2.
Note: I just ran into this this year. I followed the whole long route through the IRS phone system until I got to, "If you did not receive a W-2, press 3." So I pressed 3. I then sat on hold for half an hour. When someone finally answered, she told me that her department does not handle missing W-2's and I should call the customer service number. She gave me the number, which was the number I had just called that had taken me to her. I thought maybe I had accidentally pressed the wrong button so I went through the whole thing again and got to the same department, where someone again told me that this was the wrong department. She told me I should call the same number again and "carefully follow the prompts". I told her I had done that twice and both times it took me to her department. I asked if she could give me a direct number to the right department, or transfer me. She said no, she can't do that. So ... the IRS phone system is useless for this. It takes you to the wrong department and there's no apparent way to get to the right department. So I ended up calling the number to make an appointment at a local office, and they transferred me to someone who could actually sort of kind of help. Just saying. Bureaucracy.
Oh, and if you have to use this form, you can't submit your return electronically. You must print it out on paper and mail it in. But I think with most tax software, you could just type in what should have been on the W-2 for the W-2 part, but then instead of attaching the W-2 attach the 4852.