my one and only grandmother

so, my mom woke me up at 5am this morning to tell me that the one and only grandparent I had left died a couple hours ago. All my other grandparents died before I was born, and she gone. She's the first death I've ever had in my family and I don't know how to cope. My mind tell me to cry and heart tells me to stay strong. I don't know what to do.