Direct Subsidized and Unsubsidized loans (also referred to as Stafford loans) enter repayment after a six month grace period following your graduation or when you are no longer enrolled in school at a half-time enrollment status. Each individual loan only has one six month grace period, so if you leave school and then reenroll each of your loans may have a different amount of time left on their grace periods.
Some lenders will inform you of different payment plans available, while others will automatically assign you to the standard repayment plan. Regardless, it is your responsibility to contact your lender and choose a repayment plan.
The standard repayment plan consists of 120 equal monthly payments, with a minimum payment of $50. This plan is advantageous because you will pay less interest that with any other payment plan. If the standard repayment plan payment is too high, contact your lender to discuss other payment plan options.
You can estimate your monthly payments under each repayment plan using the Department of Education's free repayment estimator: https://studentloans.gov/myDirectLoan/mobile/repayment/repaymentEstimator.action