Search various computers on AD

I have 1,500 computers on my Active Directory list. I want to delete those who are not able to log in for the last few months. But my problem is I don’t know much about AD and I don’t know where or how to locate various computers in Active Directory. And also, I want to make my work fast. Is there any tool that can illustrate some ways to insert multiple computer names? Please help me. Thank you.
