If you are making payments to the school, then the school would be your lender. If you are making payments to the government, then the government would be your lender, however, in general, if you received a federal student loan, the US government is not listed as your lender. They would have a servicer such as Navient, Sallie Mae, or MOHEALA that you are making your payments to. You can log into wherever you are making your payments to find out the name of the servicer and the amount of interest you paid.
If you have not started repaying your student loans, and have not paid interest on the loans, you do not need to enter any information about the loans on your return.
Student Loan Interest