Do I get a write off for paying student loans?
Maybe. See https://www.irs.gov/publications/p970/ch04.html
Generally, personal interest you pay, other than certain mortgage interest, isn't deductible on your tax return. However, if your modified adjusted gross income (MAGI) is less than $80,000 ($160,000 if filing a joint return) there is a special deduction allowed for paying interest on a student loan (also known as an education loan) used for higher education. For most taxpayers, MAGI is the adjusted gross income as figured on their federal income tax return before subtracting any deduction for student loan interest. This deduction can reduce the amount of your income subject to tax by up to $2,500.
Read the whole document to be sure, but that's the basics.
You'll have to fill out a 1040 or 1040A to claim a student loan deduction. It won't be on the 1040EZ. You do not have to itemize though.
What kinds of write-offs and credits are available for someone who is single and lives in an apartment with two roommates?
As a practical matter, in 2016 you'll get the standard deduction for someone who is single ($6300) and the personal exemption ($4050). It's extremely unlikely that you'll be able to deduct more by itemizing. Most people who itemize are taking a mortgage interest deduction. Major medical bills are another possibility, but they have to be more than 10% of your adjusted gross income (it's one of the lines on your tax return). Assuming you rent and are reasonably healthy, you are unlikely to have enough to itemize.
The most likely additional deduction would be the one for an IRA (Individual Retirement Account). Although you might be better off doing a Roth anyway (no tax deduction).
If you are self-employed or making more than $100,000 a year, there are additional issues. But most people aren't. If you filled out a W-4 and will get a W-2 back, you aren't self-employed. Hopefully you have a rough idea of your annual income.
The first $9275 over your deductions will pay 10%. After that, up to $37,650 you pay 15%. The 2016 link above has a link (PDF) to the full table if you need more than that. Note that that is the first $48,000 in income with your $10,350 in deductions.