Yes, the 1120 form is just for income tax purposes, as payroll taxes withheld by businesses are handled differently by the government. For this first time for your business, you can complete the 941 form and mail it in with the 941 form and the 941 Voucher. Here is a link to the form: https://www.irs.gov/pub/irs-pdf/f941.pdf (Note: the 4th Qtr 941 form and payment would have been due by January 31, 2018.)
In the future, though, the IRS will more than likely want your business to pay the payroll taxes online through the IRS Electronic Federal Tax Payment System® tax payment service site each month (https://www.eftps.com/eftps/). You will need to be registered and become set up with them to make the payments electronically. See IRS Publication 15 (Employers Tax Guide) below as it covers everything related to payroll tax reporting
https://www.irs.gov/pub/irs-pdf/p15.pdf
